Product: Student loan

After owing for student loans with XXXX for my son and XXXX University for self, for so long, I received a phone call on XXXX XXXX, XXXX, and I made a payment of {$50.00}, to XXXX, on my student loan, that was obtained in XXXX, with a promise to pay off the loan for good when offered to do so when I received my income taxes. On XXXX XXXX, XXXX, I paid {$1400.00}, to pay my account off in full. I did not receive a final statement, but I paid this amount via my checking account, see information attached. My student loan was finally paid off, I was very relieved and satisfied that this account was paid in full, no more statements, no more phone calls. 
One year and two months later, I receive a statement dated XXXX XXXX, on XXXX XXXX letterhead, with the statement billing date for billing period XXXX to XXXX, stating that I owe {$5300.00}, for my student loan. I received a statement dated XXXX XXXX, XXXX, on Enterprise Recovery Systems , Inc. letterhead, stating that I owed {$1400.00}, the amount I paid off, on XXXX XXXX, XXXX, minus the XXXX cents and another amount of {$5600.00}, totally {$7100.00}. 
I received a statement dated XXXX XXXX, XXXX, on XXXX XXXX letterhead, stating that I owed {$1800.00} and {$2900.00}. I spoke with customer service agent, XXXX, at XXXX, from XXXX XXXX, on XXXX XXXX, XXXX and requested a statement of my loan and status. I received a statement dated XXXX XXXX, XXXX, ( see attached ) from XXXX XXXX, regarding my request, stating that my loan was charged off on XXXX XXXX, XXXX and the other was charged off on XXXX XXXX, XXXX. After Enterprise Recovery Systems, Inc. received this information I received from XXXX XXXX, explaining my loan status, I began to receive statements from XXXX, stating that I owe a balance of $ XXXX. 
At this time, my loan was in the hands of Enterprise Recovery Systems , Inc. when I paid the amount of {$1400.00} on my loan, and was told that my loan would be paid in full, by paying {$1400.00} on XXXX XXXX, XXXX. I was not notified of any payments for one full year. I had every reason to think that my loan was paid in full. When I received a notice one year and two months later in XXXX of XXXX, it was then that I became aware that something was wrong. I spoke with several people from XXXX, and nothing was ever done about the {$1400.00}, that was paid on XXXX XXXX, XXXX, as if nothing had happened and the money I showed as having paid, just disappeared and no credit was recognized on my student loan that it had been paid in full. I can not afford to give money away and I want to pay my bills. At this time, I am presently attending XXXX and I am unemployed and do not want to pay for something that has been paid many times over. I filed a complaint with the XXXX on XXXX XXXX, XXXX, XXXX : XXXX, Complaint ID # : XXXX, Business Name : Enterprise Recovery Systems , Inc . 
On Tuesday, XXXX XXXX, XXXX, I received a call from XXXX XXXX, who offered me a pay-off amount, I explained that this loan amount was paid and I do not owe any monies for this loan. XXXX XXXX asked me to send him an explanation of my account and to fax it to him ( see attached ). I faxed a letter stating the same information I 'm explaining to you. On XXXX XXXX, XXXX, I forwarded my statement to XXXX XXXX at : XXXX. On XXXX XXXX, XXXX, I received the following statement at my XXXX email, stating : ( attached ), Current Principal Balance ( not including interest ) : {$7000.00} Outstanding Interest : {$55.00} **Interest accrues daily