Product: Student loan

Loan repayment for XXXX student loans co-signed by my mother began to XXXX XXXX XXXX in XXXX. Payments were made regularly and on time. Unfortunately, in XXXX my mother had to file bankruptcy. She was told the student loans would not be included, but they somehow were ( by an inept young attorney ) because repayment was halted anyway. 
The whole bankruptcy was handled poorly and a year later in XXXX the bankruptcy had to be dismissed, because it was never confirmed. By the time my mother learned this, that lawyer had been fired and no company had been ( nor could have been ) paid by the trustee without confirmation. My mother was then contacted in XXXX XXXX by National Enterprises Systems to begin repayment. The loans had been discharged by XXXX and referred to National Enterprise Systems. XXXX provided no evidence of repayments faithfully made to them from XXXX. Therefore NES charged to original loan amounts to my mother and a repayment plan was established between her and NES. Since that time NES has kept poor records, applied payments as they saw fit, and not given credit to the accounts for payments. They misapplied payments to whatever account they saw fit then sent those account 3 times to other collection agencies arbitrarily claiming no payments had been made. There were times they claimed to have no record of these loans as a deliberate attempt to discredit repayment of any kind. My mother filed a complaint with you # XXXX and later sent a very large file ( with same complaint # ) documenting resumption of payments dating back to XXXX. Is there any way she can get proof of payments as far back as XXXX to XXXX too? My mother XXXX XXXX XXXX XXXX pieces of information from NES to which they only responded to XXXX XXXX XXXX ). That came in the form of XXXX XXXX XXXX XXXX different letters regarding only XXXX XXXX of XXXX ) account which listed to different balance. My mother made monthly payments on these accounts a now they are harassing me with letters demanding the original amount. 
My mother is and has assumed repayment, but balances are simply not right, unfair, and truly not reflective of payments made. Why am I being harassed if/since payments are being made. We do not trust this agency, because there have been too many times when payments have not been applied or applied as agreed. I am requesting an adjustment on the balances that reflects the numerous payments ( in good faith ) that have been made to this company. Is there a statue of limitations at all or recourse for the debtor for such unfair practices? I will check XXXX box for my problem with this company, but I really need to check all boxes. My mother had agreed to repay and has informed this company of this. She has tried to work with this company but they refuse to co-operate. We believe they have forwarded these accounts to another company as my mother received a call on her cell and at home from an unknown source this past Friday XXXX/XXXX/XXXX. Since she did not make the call, had not heard of that company, and the rep said the call would be recorded, she told them to send her a letter stating their business. The company was either XXXX or XXXX XXXX 
The account numbers have been repeatedly changed, so as to confuse things and double charge. So has this company 's address. The original address was XXXX XXXX XXXX, XXXX, OH XXXX. Now it has changed. See company information. My mother and I continue to receive bad information, have trouble with customer service, and certainly do n't agree with the fees charged.