On XXXX XXXX, XXXX I entered into a real estate installment contract with The XXXX XXXX for the purchase of a mobile home. The amount financed was XXXX and the interest was@9.50 % totaling a finance charge of XXXX for a contract total of XXXX. At some point in XXXX XXXX sold This contract to Green Tree Servicing. I received notice of this via a monthly statement from GT. I continued payments never missing one payment and incurring a late charge. On XXXX/XXXX/XXXX I received a notice from GT That my loan was seriously delinquent and I phoned GT and spoke to a XXXX XXXX who reviewed my account and informed me that my loan was, in fact, paid in full. She further stated that there was an error in the interest calculations. I made a total of XXXX payments totaling XXXX against a contract total of XXXX resulting in an over payment of XXXX. I therefore cancelled my last payment of XXXX and expected this matter to be taken care of. In XXXX of XXXX I spoke to a manager named XXXX XXXX who informed me that the error was recognized and would be corrected and written off. I heard nothing more from them until I received a letter from them dated XXXX/XXXX/XXXX stating that I owed them XXXX. I contacted the number on the letter and was informed that my account had been turned over for collection. They would not listen or accept any information to the contrary and wanted their payment. I refused to pay a debt that I did not owe. I called for XXXX XXXX, XXXX XXXX and a lady named XXXX and was unable to get in touch with anyone. Next I started receiving a multitude of calls from various collection agencies and explained to each of them that I did not owe this " debt '' finally the calls stopped. Today I received a letter from GT That showed a new creditor XXXX. and that it was an attempt to collect a debt. This is the operable straw that broke the camels back. Enough is Enough.I do not owe these people any money! If I had any inkling or could be shown any documentation that I did I would have paid them a long long time ago.