MTN Contract

I am not happy with the service i have received from MTN, i cancelled my contract three months ago and after a month my account was debited. I called and i asked the consultant why is my account debited whereas i dont owe anything my account has been fully paid up, she said she will find out and come back to me till today there is no call from MTN consultant.

I called this morning and i was told that i need to go the police station to do an affidavit and come to my suprise if i dont have an account, how will they attach the evidence if i dont have any records with MTN and where does the money goes to?