Product: Student loan

In XX/XX/XXXX, I received a letter stating that my student loan payment was late. 
( I have not made a payment in 10 years. I paid off my consolidated {$47.00}, XXXX loan to Sallie Mae when I refinanced my home on XX/XX/XXXX. ) I called Navient to find out what the payment was for. I was told that the person on the phone did not have access to my records but they would look into it and contact me again. I did not hear back from them. This happened 2 more times. 
In XX/XX/XXXX, I applied for a mortgage and was denied because my credit score was too low. On XX/XX/XXXX, I spoke with XXXX from Navient. XXXX informed me that on XX/XX/XXXX, My loan was transferred to a private loan. I asked " What private loan? '' I was told that XXXX needed to submit a " Payment research request '' and it would take 7-10 days to get an official answer. 
On Navient 's website, I can see a - {$47000.00}, a + {$47000.00} and another - {$39000.00}. I also see a balance due of {$8800.00}. I asked why the funds were posted and then removed and why only the {$39000.00} was posted back. Navient had no answer and I was told that I would need to wait for the " research request '' to come back. 
On XX/XX/XXXX, I called Navient again. I spoke with XXXX. XXXX could see the payment of {$47000.00} on XX/XX/XXXX. She could also see the " research request '' and told me the estimated date of completion for this was XX/XX/XXXX. I asked her if this could be expedited as my mortgage application was being denied due to this error. ( I still did not know what money was owed. ) I asked to speak with a supervisor. I was transferred to XXXX. 
XXXX explained that there was a " parent plus '' loan ( my son 's ) which was paid in full on XX/XX/XXXX. I have no record of these loans, so I asked for a copy. I have not received it. XXXX told me that I can not see the loan on Navient 's website because it was paid off so long ago ( 10 years ). I asked XXXX why this suddenly because accountable 10 years later. XXXX said she would expedite the " research request ''. This now would take 3-5 business days. Meanwhile, my mortgage application was still waiting in the wind ... 
On XX/XX/XXXX, XXXX called me. She stated that there were two parent plus loans that were paid off on XX/XX/XXXX. XXXX told me that I VERBALLY requested funds from the paid off consolidated loan be redirected to pay off the parent plus loans. I have no recollection of this transaction. Nor can I fathom the reasoning behind such an action. I can not even understand how this could be done. The consolidated loan was paid off for 3 months already ... How could funds be redirected after a loan was closed and paid off? 
To add insult to injury, I was told that the {$39000.00} was applied as a " payment in advance '' to my consolidated loan. Therefore, no payments were due until the {$39000.00} funds were depleted. This is one of the most bizarre things I've ever heard. 
I requested a copy of all documents regarding ALL loans. XXXX told me they would take approximately 7 days to gather and then they would be sent out. 
I specifically asked for copies of the " parent plus '' loans in my son 's name as I have no record. I also asked for any documentation regarding the alleged VERBAL transfer request. I was sent a copy of the Account Payment Information sheet showing the loan payment. I was also sent copies of correspondence beginning in XX/XX/XXXX. ( I already had these. ) I was NOT sent anything else. No records of my son 's parent plus loan ( the  one the XX/XX/XXXX was applied to ) or any statements. 
XXXX also told me that correspondence was sent to my email account regarding the payments. She said I could see all the history on Navient 's website. I logged on. The only emails I received began in XX/XX/XXXX. The same time I received paper notification. 
If I agreed to this transaction, why are there no monthly statements? There are no letters, statements or other transactions for 10 years! Nothing posted on the website regarding the monthly disbursements of the {$39000.00}. 
How can this happen? 
I was told there was nothing that could be done regarding the payment and in order to resolve the issue, I would have to pay the current balance due including late fees and interest. I requested that I be allowed to pay off the original balance and forgive the interest as I was unaware of any outstanding loans. I was told this was NOT possible. 
In order to repair my damaged credit report, I reluctantly paid the original balance of {$8800.00} PLUS and additional {$6300.00} in interest fees and {$90.00} in late fees. 
This was totally unexpected and has put an undue burden on our budget as my wife and I are recently retired and living on a fixed income. 
Thank you in advance for anything you can do for us. Please let me know if you need anything else.