TVS Credit Services Ltd — Mobile phone purchased

I purchased one Samsung mobile phone through TVS credit from Sivakasi Samsung showroom(Kaliswari enterprise). Every month properly I paid the due amount at the due date( before 10th date). I paid the due amount(cash) through TVS credit loan section employee (Sivakasi) Mr. Muthupandi because of bank account signature mismatched. That time he said, no issue I will come and collect the due amount. I too paid the due amount and get the receipt, sometimes not given the receipt. Now the problem is outstanding amount of Rs. 4400, why should I pay the amount. Every month I paid properly the due amount. Kindly you have to check with employee and verify and do the needful.