Complaint sub-issue: Trouble with how payments are being handled

My complaint is regarding my Student Loan Servicer Nelnet. I have attempted multiple times by contacting the Nelnet customer service, the XXXX complaint line and The XXXX XXXX all with no resolve. Nelnet continues to be unable to provide answers to my inquiries regarding my student loan accounts. Also when attempted, Nelnets answers contain contradictory information or unsatisfactory explanations. I feel my rights as a consumer have been violated as well as I have endured unnecessary stress to my self and thus my family members. 

Most recently, during my annual recertification of IRB plan, I became aware of the interest forgiveness available in the REPAYE that was not available in the PAYE while speaking with a Nelnet representative. The Nelnet representative ensured me that there would not be a problem for me to make a change to the request to REPAYE. I sent in the PAYE application on XX/XX/XXXX and also spoke with a Nelnet representative the same day who corrected my application over the phone and emailed me the updated version with the request to change to the REPAYE. This application was signed and then faxed on XX/XX/XXXX with my two most recent paystubs to verify my income. I received information from Nelnet that my payment had been calculated to {$140.00} month.
After careful attention to my account, it became clear to me that Nelnet had made a mistake by processing the application request for PAYE instead of REPAYE. I made 3 monthly payments of approximately {$140.00} or more by  the date provided on the monthly statement mailed to me via US Postal mail by Nelnet during the dates XX/XX/XXXX-XX/XX/XXXX.
I began receiving emails from Nelnet in XX/XX/XXXX stating my account was behind and late although I had made payments on time per the billing statements I received from Nelnet. I contacted the XXXX compliant line and initiated a case, as Nelnet would not address my concerns. In their attempt to correct their mistake while processing my REPAYE application my payment increased to ~165.00 $ month per a Nelnet representative.
I do not wish for my account to be considered late when I am paying the amount billed to me. I have continued to ask for someone to explain to me how my payment increased when both the PAYE and REPAYE are IRB plans. During this three month process when I expressed concerns to Nelnet forbearance was offered to me as a solution and I feel this offer is completely inappropriate considering the interest that I would accrue while bearing their mistake of incorrectly processing my application. Incorrectly processed, despite my clear communication with their representatives both during and after the process. 
In previous years when processing my IRB application with Nelnet I accepted their offers of forbearance, as I was not as knowledge at those moments in time. In the year of XX/XX/XXXX, I was forced into forbearance as my application was not accepted as it was processed as blank & incomplete per Nelnet. This again was an error of Nelnet, pure negligence and poor customer service. I called and spoke with multiple customer service representatives trying to explain that the reason page number 3 was blank and therefore incomplete per Nelnet. This was due to none of those questions on page 3 required my attention or applied to my situation. The application was sent in 3 times with an ~ 2 month forced forbearance as I could not make the minimum monthly payment towards my loans while not in an IRB plan.
Again, if my application was processed efficiently and/or my concerns taken more seriously forbearance most likely would have been avoided and the additional interest accrued toward my principal also avoided.
I take my credit score and financial obligations seriously. Nelnet has demonstrated multiple times that they do not wish to provide adequate answers to my inquiries, nor timely and efficient processing of applications, consistent and courteous customer service and to maintain the consumer bill of rights to those who are auto assigned to their entity as student loans serving company.