Product: Student loan

I have been on an income-based repayment ( IBR ) plan since I began repaying my federal student loans in XX/XX/XXXX, as I work in public service and am on track for PSLF. Every year I have to recertify for an income-based plan by authorizing XXXX XXXX to view my tax information and determine my monthly payment amount based on yearly income. For this year, I recerified online on XX/XX/XXXX before the deadline of XX/XX/XXXX and received confirmation from the IRS that my information was accessed by XXXX. On XX/XX/XXXX, I received a message from XXXX XXXX   saying they were changing my loans to a standard repayment plan rather than an IBR plan, which would cost me significantly more than I can afford per month. When I called, I was told this is because they never received my IBR application, though the customer service representative looked into it and acknowledged they did in fact receive it and this was a mistake. Because of this mistake, XXXX never processed my IBR application and still to this date has not completed it and informed me of what my monthly payment amount will be. 
I have called XXXX customer service 5 times in an attempt to resolve this issue [ on  XX/XX/XXXX, XX/XX/XXXX, XX/XX/XXXX, XX/XX/XXXX, and XX/XX/XXXX ]. During each call I have been told to do completely different things in order to have my application processed ; I have followed the instructions of all 5 customer service representatives, and each time nothing happened and my application did not get processed as I was told it would be. The first and second times I called, I was instructed not to make any payments ( as they would not qualify for PSLF ) until my IBR application was done being processed. They assured me it would be resolved by the end of XXXX so I will not have to worry about delinquency or reports of non-payment to credit agencies. This instruction was reiterated to me in follow up calls when I asked if this was correct, as so much time has gone by that I have been getting past due notices from XXXX. When i called a third time on XX/XX/XXXX because my application still had not been processed, I was told I just had to pay a {$5.00} fee to have my IBR application processed ; the representative said I would receive a bill within a week and once I pay it the application would be processed within 1 month. I never received a bill so I called back on XX/XX/XXXX and was told I could pay it over the phone via debit card. I of course paid right away over the phone, and was told it would take 1-3 days to have the application processed and find out what my monthly payment amounts will be. When I last called on XX/XX/XXXX, I was told that a request to have my application processed was submitted on XX/XX/XXXX, and the customer service representative said he submitted a second request to have it processed. He said I would hear back within 3 days of that last call. However, it has been 2 weeks and still nothing has changed and my account has not been updated. 
All of my federal student loans are in forebearance status until XX/XX/XXXX ; each time I call they resubmit the application for forebearance so they have a few more weeks to process my IBR application. 
As a result of this ordeal, I have not made any PSLF-qualifying payments since XX/XX/XXXX, since I was directed not to make payments in XXXX, XXXX, and XXXX. This means it will now take me 3 ( more if its not resolved by the end of this month ) months longer than it otherwise would have to make the 120 payments required to have my loans forgiven. It is completely unacceptable that XXXX XXXX can not complete such a routine process within a reasonable amount of time. I will likely have to call again this upcoming week, but I dont know if theres anything else I can do to get them to just process this application like they say they will do each time I call.