Product: Student loan

I joined the XXXX in XX/XX/XXXX with the Student Loan Repayment Program ( SLRP ) in my contract. I applied for the SLRP after the first year of service, like directed to. I received paperwork XXXX from XXXX signed on XX/XX/XXXX. I filled out my section of the XXXX and sent it to my loan servicing agent ( American Education Services aka AES ) on XX/XX/XXXX. There were XXXX separate SLRP XXXX for each of my XXXX loans ( XXXX Federal, XXXX Private ). After receiving XXXX applications from me, AES filled out their section, signed and dated on XX/XX/XXXX, and sent it directly to the XXXX as instructed to complete processing. 
The Issue : AES sent only XXXX SLRP applications out of the XXXX loans applications that were sent to them by me ( These XXXX SLRP applications were for the XXXX Federal loans only, not for the Private loans ). According to AES there was a note on my account that the XXXX Private loan SLRP applications were not approved due to a date discrepancy ( over 60 days between the XXXX signed and dated box XXXX and that they sent a letter via REGULAR MAIL ( not certified ) as the only way of contacting me about the issue. 
Later on XX/XX/XXXX, I was told that the Federal loan apps may have gone through but the private loans did not probably because the applications went to 2 different departments ( one for federal, and one for private ) but they may or may not have had different standard of accepting the dates provided on the XXXX. ( How can one department within AES that handles private loans have significantly different standards than a department that handles federal loans ; and why was n't I notified that these would be going to be processed by 2 separate departments ) I had never received that letter of denial notification, nor was I notified in any other way that those XXXX SLRP private loan applications had been denied ( most likely the physical letter got lost in the mail, or put in the duplex neighbors ' mailbox mistakenly. How could I have known these were denied and since this letter was not sent certified, there was no certainty that I would receive any notification besides my own in depth investigation? 
At the same time, XXXX had made a payment on my AES account which had indicated to me that XXXX had received all necessary paperwork and AES did what they were supposed to with the paperwork I provided. The lump sum was dispersed to both federal ( the XXXX where paperwork went through fine ) AND to private loans ( the XXXX that apparently did n't have correct paperwork ). AES told me they disperse payments to wherever XXXX directs them to, XXXX told me they have no control over where the money is dispersed after it leaves their hands ) XXXX ( XXXX ) made payments to ALL of the XXXX loans, indicating to me that all XXXX SLRP applications were received and processed. ( Why would I think otherwise? ) Payments were made on XX/XX/XXXX ( dispersed to all XXXX loans ), XX/XX/XXXX ( dispersed to only federal loans ), and XX/XX/XXXX ( dispersed to only federal loans ). 
Because payments were not being made on all loans, and was only a portion of the payment I was entitled to, interest was accruing on a higher balance that what it was supposed to be. 
[ Interest rate x current principle balance / # days in the year ] = daily interest According to this equation provided by AES, my daily interest rate should have been significantly less if the correct payments were made in XX/XX/XXXX, XX/XX/XXXX, and XX/XX/XXXX. 
I sent new paperwork on XX/XX/XXXX to AES to be filled out to REDO the SLRP process that had been messed up in XX/XX/XXXX. Private loan applications are currently being processed at XXXX for payment to AES.As the time passes for me to investigate all of the mishaps and miscommunications, my interest is continuing to accrue. I now owe over {$18000.00} due to interest rate accrual, which should be significantly less if done correctly in XX/XX/XXXX. 
AES misled me, the customer