Product: Student loan

When my student loan was sold to Nelnet for servicing I was offered a lower incentive interest rate ( 4.125 % rather than 5.625 % ) for making the first 36 payments on time. I did and my interest rate was lowered in XXXX. In XXXX I began making large payments on my loan, roughly {$1000.00} per month. I was trying to pay down the principal and when I inquired to Nelnet as to the best way to do so, I was told to simply make the large payments. Because I was making large payments I would receive monthly statements from Nelnet indicating that I did not owe a monthly payment and that I was current through XX/XX/XXXX. I switched to a lower paying job in XXXX and did not make any payments. I continued to receive monthly statements until XX/XX/XXXX reflecting that I did not owe anything. I picked back up with payments in XX/XX/XXXX and received a letter that I had lost the incentive interest rate earned in XXXX and that my interest rate was being raised to 5.625 %. When I called XXXX to inquire as to why, I was told that my loan had been transferred, that XXXX had missed a payment and that it was an error. My interest rate was adjusted back down to 4.125 % for one month. In XX/XX/XXXX I received another letter stating that my interest rate was again raised. When I called Nelnet to again inquire as to why and was told that my payments were not on time. The first individual with whom I spoke stated that, although I did not owe Nelnet any money in XXXX and was sent statements reflecting as such, my interest rate was being raised because my payments were not on time in XXXX. When I asked to speak to that person 's supervisor I was told that I lost the incentive interest rate because I did not make payments in XXXX, even though Nelnet continually sent me statements that said I did not owe any money and that I did not owe a payment until XX/XX/XXXX. I asked to speak to that person 's supervisor, who then told me that I lost the incentive interest rate because my XX/XX/XXXX payment was due on XX/XX/XXXX and I'd made it on XX/XX/XXXX. I pulled up my online statement, which shows my XXXX payment on XX/XX/XXXX. I was then told that my payment was not 'on time ' because it was too early. It was explained that this was the case even though when the money was due ( XX/XX/XXXX ) it had already been paid on XX/XX/XXXX and I did not owe anything on the " due '' date. The Nelnet supervisor agreed that I was not ( and still am not ) delinquent on my payment and that I had never made a late payment. I asked where in writing I was notified that by making a payment too early, or making large payments throughout XXXX ( as Nelnet instructed me to do ) I would lose the lower interest rate. I was told that this is not in writing, but because it is an incentive Nelnet could simply raise my rate. The supervisor was looking further into the matter. Today I received another call from Nelnet and the individual with whom I spoke told me that I lost the incentive because my payment due XX/XX/XXXX was not paid until XX/XX/XXXX. This is now the third reason I have been given for losing my lower interest rate. Nonetheless, the individual with whom I spoke also agreed that my account is current and that my payments have not been late or too early. Regardless, I made a payment on XX/XX/XXXX and my XX/XX/XXXX payment was not late. Nelnet could not explain why it has taken almost 2 years for it to notice this alleged late payment, but their own records show my XX/XX/XXXX payment. To summarize, Nelnet acknowledges that my account is current, I have never made a late payment and it sent me statements for over a year that reflect that I do not owe it any money. It has now given me three different reasons why my interest rate was raised, but admits that none of the justifications it has given are actually in writing anywhere. Nelnet can not give me a legal/contractual reason for raising my rate, or any factual support for doing so.