cancellation of contract

i have had a contract with cell c about 3 years ago, it expired around a year ago , and ive decided to cancel that contract , they however , couldnt do it at the store that took out the contract, (kinda manipulative to activate but cannot assist in cancellation at the store). then trying to obtain the no for cancellation was like almost impossible, after getting threw. we cancelled it , they said it would take a month for it to go threw , after two months, my account was still being debited, i called again , same story , im still being debited a year after my contract expired, what do i do.