Product: Student loan

Due to financial struggles, I have been having a hard time making my student loan payments. Regardless, I have always made sure they never defaulted and I made the necessary payments to stay afloat. On XX/XX/XXXX of XXXX I called and scheduled a payment to make the minimum payments in order for my loans not to default. I have provided a detailed time line below to somewhat keep this portion as specific to the narrative as possible. I was told that my debit card payments were unsuccessful and they would schedule one for the following day, Well unbeknownst to me, a payment was put through on the XXXX of XXXX and another payments was scheduled for XX/XX/XXXX. After the three days it takes to process the loan, I was charged on both the XXXX ( for the original payment on the XXXX over the phone ) and the XXXX of XXXX ( the scheduled payment by the representative who told me my first attempt was unsuccessful ) for two separate payments of differing amounts. The issue that arises is that I had enough funds to clear the original payment, but not enough for the over payment which forced my account into the negative. 
I called to rectify this issue on XX/XX/XXXX and was told I would be refunded the full amount and an additional amount for the inconvenience and the overdraft fee ( {$50.00} ). 
On the XXXX of XXXX, my bank reversed the charges that put me into the negative. Only two of the payments were reversed ( XXXX ) {$290.00} ( XXXX ) XXXX ) ) as I had enough funds to clear the smaller loan for {$14.00} that cleared on the XX/XX/XXXX @ XXXX XXXX. 
The following day, XX/XX/XXXX, the refund from Sallie Mae was put into my checking account This is where things become an issue. I call to confirm with a representative that all my accounts are in order and I am told I am fine. A few days later I check my Sallie Mae app to see that the amount owed on my loans is ridiculously lower, and as I look [ LOAN # XXXX ] is missing entirely. There is no payment from XX/XX/XXXX that cleared, nothing. I call Sallie Mae to see what the issue is and I am told that my loan defaulted and was sold off and if there was anything that I needed I could be transferred to the correct department. After calling my father to let him know the situation, I call Sallie Mae back to contest that I did indeed make a payment in the end of XXXX that was the necessary payment to keep it from defaulting and that is what brings me here. 

After being thrown through multiple massive loopholes and being told constant disinformation from multiple representatives I didn't know what to believe. I've been told I was ignorant, that I didn't understand how banks work, that I never made the transaction, that the transaction was denied for insufficient funds, that I did make the payment but they can't see where the payment was made too, and have been hung up on my fair share of times. The question is where is the money? I was refunded for Sallie Mae 's own negligence and after calling to be refunded for the money from the overpayment, my original payment disappears into thin air. I'm out {$310.00} and now my credit will plummit and I defaulted on a student loan I for sure made a payment on. No one is able to tell me what happened with this payment or where it went until I finally request a supervisor. I am put in contact with XXXX and the circus starts again. At first, I never made the payment, then it was the payment was rejected, then it was I never made the payment again. Finally, she tells me to send her my bank transcript and I send her screenshots off my Iphone of my bank statement from weeks prior. She directs me to upload.salliemae.com and says she will call me back in a few days. After over a week of calling her to get in contact and being transferred everywhere but to her line, XXXX tells me that those transactions could be holds and that that isn't sufficient enough information and that the transcripts prove nothing. 
I ask to speak to a person of higher authority and I am transferred to XXXX XXXX. She tells me that I need to get my bank on the line and confirm that the payment was made, authorized to Sallie Mae and those funds were successfully released. After a week and multiple attempts to get the both of them on the line in order to either confirm or deny this information ( side note : I have already called and confirmed with my bank several times about this transaction as Sallie Mae has consistently told me that it is nothing on their end ). My bank confirms that the payment withdrawn on XX/XX/XXXX was succesfully authorized and released to Sallie Mae, that it was not rejected nor returned. XXXX XXXX said this was all she needed and if I could send her a copy of my transcript as well she can get this issue solved. 
A week later she calls and tells me that her department did their research and my transcript shows that I never made that payment and I had insufficient funds. I argue with her for two hours, walk her through my transcript day-by-day, transaction by transaction, and she contradicts her sentiment and statements made the week prior. She says that the call with the bank was satisfactory yet she was the one who ended the call. If she needed more information she should have simply asked. If the information presented wasn't enough, why did you hang up the phone call and tell me that was satisfactory. I question how did I get a refund for a transaction that was returned to me and never processed but the original transaction I made the day prior where my transcript shows you I had the necessary and available funds to make the transaction was denied for insufficient funds? She eventually grew irate with me and told me she wouldn't help me anymore and I basically was XXXX and if I wanted to go ahead and file a complaint I was free to do so. 
My bank confirmed that transaction was made to keep my loan from defaulting and even with the evidence they asked for and was provided, Sallie Mae refuses to take any ownership and now my loan has been sold off and my credit score will be impacted greatly. For a payment I did make and if it was rejected, when did that money return to me? I asked that XXXX times and then was told that the money was only held by XXXX XXXX, not actually taken out. When I asked her how a transaction from two months ago on my official bank transcript would should something being held, she had no answer. I have more information and I am in the process of trying to create a timeline but while I wait on the affidavit from my bank confirming the transaction, I wanted to submit this and have documentation. 

Important Dates : XX/XX/XXXX Date of initial over-the-phone payment. I was told by the representative of Sallie Mae that my card wasn't successful in making the payment, therefore, we would schedule a payment the following day ( XX/XX/XXXX ). A payment was successfully made this day, unbeknownst to me ( see transcript from my bank to confirm, it takes XXXX days for Sallie Mae to process payments ) XX/XX/XXXX The scheduled payment the representative set is authorized, causing a double payment for the same original payment I called to make the day before. 
XX/XX/XXXX The original payment that I was told was unsuccessful on XX/XX/XXXX over the phone is withdrawn from my bank account in the amounts of ( XXXX ) {$14.00} [ LOAN # XXXX ] ( XXXX ) {$300.00} [ LOAN # XXXX ] ( XXXX ) {$310.00} [ LOAN # XXXX ]. Things to notice here, I have available funds when this original transaction is made. This is a copy of my transcript, not a mobile banking app or anything of the sorts. These are transactions where my account was credited with three individual payments ( although they were all made at the same time and then distributed to the specific loans. ) XX/XX/XXXX The over payment is withdrawn from my account in the forms of ( XXXX ) ( {$14.00} ) [ LOAN # XXXX ] ( XXXX ) {$290.00} [ LOAN # XXXX ] ( XXXX ) {$310.00} [ LOAN # XXXX ]. These are over payments, due to the constant issue I have been having with Sallie Mae. I was charged twice, this time pulling my account into the negative. As you can see, I do not have the available funds in my account for this transaction. There is not the money in my account for these transactions to go through. On this date, I also call Sallie Mae and ask for a refund for the overcharged. They tell me they will rectify the issue and for the overdraft fee they will cover that with an extra {$50.00} for the refund. 
XX/XX/XXXX My bank reverses the payments for THE SECOND OVER PAYMENT ( the transaction from XX/XX/XXXX ) in the amounts of ( XXXX ) {$290.00} ( XXXX ) XXXX but because I had available funds for the smaller loan being charged {$14.00} [ LOAN # XXXX ] that transaction wasn't reversed. 
XX/XX/XXXX Sallie Mae refunds me for the THE SECOND OVER PAYMENT in the amounts of ( XXXX ) {$290.00} [ LOAN # XXXX ] ( XXXX ) {$310.00} [ LOAN # XXXX ] ( XXXX ) {$14.00} [ LOAN # XXXX ] as you can see in my transcript. The question is, if their argument is that I didn't have available funds in my account for the original withdraw made on XX/XX/XXXX for the original transaction, how did you refund me for a transaction that my bank reversed and you never received those funds? It doesn't make sense but every time that I ask that question, the topic is changed and it is ignored. 
XX/XX/XXXX XXXX XXXX calls me in the morning and leaves a voicemail saying that she has to speak with me. Call her back and all the information I have provided and the phone call with my bank wasn't enough nor credible. When asked why she didn't question the bank any further or ask any questions, as she was the one who initiated the end of the conversation and said that the information she received was more than enough to prove that I ( 1 ) made the payment and ( 2 ) it was authorized and disbursed to Sallie Mae, she raised her voice. After two hours on the line and XXXX. XXXX virtually telling me that even though my bank transcripts show that the money was distributed to Sallie Mae and it never was returned to my account, and that my bank confirmed that the money was never returned to me, she said she was finished with this conversation and had no more time for me. She retracted statements she said the week prior and after guaranteeing I had enough information the week prior, proceeded to tell me that I was virtually out of luck. 

Please call and let me explain over the phone as well as the amount of typing makes the computer time out. I am in the process of getting an affidavit from my bank stating that the transactions were successfully made on their end and that specific transaction was never returned. All I want to know is where did that money go that was supposed to keep my loans from defaulting, at this point, Sallie Mae refuses to take any responsibility nor help me anymore as said by XXXX XXXX the manager. I am trying to also get access to all of my recorded phone calls with Sallie Mae over the course of the past two months but again, they're giving me trouble.