Product: Student loan

I was switched from Great Lakes to Nelnet and began repayment with them on auto pay. Payments for XXXX, XXXX, and XX/XX/XXXX went through without issue. XX/XX/XXXX I received an email from Nelnet stating my payment did not process successfully. I had sufficient funds in my account. I called costumer service and was told 1- I did not have balance due that month ( costumer service rep could not tell me why I did not have a payment due that month ) and 2- the account number for my autopayments stated there was no account with that number. The costumer service rep verbally confirmed the account number with me and found it was incorrect in the computer system, she stated she was updating the number while we were on the phone so that it would process next time. This had not changed from my end at the beginning of the year, so possibly the first of the year Nelnet has to copy account information over and it was transposed incorrectly on their end. XX/XX/XXXX when I logged in to make a payment my account said no payment was due that month. XX/XX/XXXX I logged in to make my monthly payment and was shocked to find that my account was stating that I had an overdue balance. I received the same email that stated that my auto debit was returned in XXXX as I did in XXXX. when I called in XXXX I was told that was because I did not have a payment due. XXXX showed no payment due on my account portal, so I assumed that was why I received the same email of a returned payment. When I saw that my account changed to saying XXXX was overdue I called and spoke to costumer service rep XXXX. She told me that my 1 the previous costumer service representative had not updated my account number, and per policy would not have been able to 2 that she could see a list of transactions of payments attempted that were returned ( this information is not available for me to see on my account page ) 3 she stated that I did not have a late fee posted to me account, I inquired why my next payment was increased if it was not a late fee and she stated that is the schedule that Nelnet uses for repayment " so that the loan can be paid off as quick as possible every 2 years the monthly payment increases. '' I confirmed on my account that I am in a standard repayment. Per Nelnet provided documentation of the standard repayment plan there are not changes in payments every 2 years. 
She did not offer any options to rectify the situation other then making a payment over the phone, I let her know that I would prefer to make it on a computer where I can take a picture of proof of payment since last time I spoke to someone on the phone they had stated they had fixed the billing issue while I was on the phone, when in reality it was never rectified. 
The online access to the loan account does not provide adequate information for the costumer ( payment due amount being inaccurate, the costumer does not get a break down of payments posted and/or returned-my account just shows my three previous payments prior to the 1st of the year and nothing that was supposedly returned payments for the account number being incorrect. ) XXXX told me both that XXXX showed no balance due because the auto payment was starting to process prior to it not going through because it had that wrong account number, and that I am not signed up for autopayment. Both can not be true at the same time. 
Attached are the identical emails about returned payments, screenshots to show that my payment plan is the standard payment plan, a picture of Nelnet 's different payment plans and that the standard plan does not include an increase in payment, screenshots of what transactions costumers are able to see on the online account.