Product: Student loan

I am making a complaint about my student loan lender Navient. The issue stemmed from a payment I paid via Navient 's online website on XXXX/XXXX/XXXX. I paid the amount for {$350.00} for my monthly payment. When I logged on the site it informed my total payment due was {$600.00} and my current amount due and current amount due was XXXX and past due amount was {$240.00}. My payment was made for XXXX and I got a confirmation for that manual payment entry. 
Somehow an additional {$110.00} was taken without my approval to total the amount of {$460.00}. I called back to complain several times about was passed around to various operators and told XXXX6 weeks for my refund. I various operators this was unacceptable and I wanted this money back immediately. They were advised they took the money from account and needed to refund it for another bill. Navient was informed that stores credit your account in similar cases promptly. Navient unlawfully went into my account and took an additional {$110.00} from my account. And tried telling me it was my error their website took the additional funds from my account. I contacted my back after getting no where with Navient they issued me the refund. 
I called Navient back and an operator cancelled my refund since my bank did it on XXXX/XXXX/XXXX. I got a check from US Dept. of Treasury for that amount when I canceled it. Navient was called on XXXX/XXXX/XXXX, and said void and shred the check when treasury told me I can send it to them. Navient now indicated to me through another operator that they could not cancel the refund they sent out. I asked to speak to supervisors and get employees that put you hold and become rude and irate. Navient now indicates the funds that were taken shows my account is delinquent. As I informed no operator that worked on my account in the last month informed me of that. And the operator stated money that what was refunded back to them and never told which loan private or federal to pay it back to. 
I am stuck between various people and the company telling me different statements. I requested a letter from the company to dispute the transaction on my credit card statement. The letter was never sent to me by the Office XXXX as I requested from them. 
The website also informed me that my income based repayment was due on XXXX/XXXX/XXXX and when I called it stated XXXX XXXX. After speaking with customer service they indicated it was due in XXXX of XXXX. Its always different the website to person you speak to and this issue is a prime example of it. I requested a senior level person to contact me as the Office XXXX is problematic. I requested several employee 's supervisors and were denied or they tried say I handle it and they do not. My issue is not dealt with and Navient has done nothing to help me. Even requested senior level Navient leadership and sent emails and was given correspondence. Inquired from several operator 's other lenders that I can switch loan to based on problems with Navient. No help was given and for that matter as requested from Navient. I called Navient 's Corporate Office in XXXX Delaware on XXXX/XXXX/XXXX, and requested a senior person based on my problem was transferred an extension with no voicemail. After the line rand twenty times the call disconnected me from the system. This is an example of the gross negligence of Navient as a financial lender. 

Was in car accident in XXXX and called in XXXX of XXXX to defer payment was told I had to pay. Even though I was requesting not to based on financial hardship to to a car accident. Had to pay regardless and requested a supervisor from customer advocate office and was denied was forced to make payment. Navient without my approval used third party XXXX for payment. These are common issues and lack of care of Navient showing negligence.