How many times do i have to cancel my contracts?

Ive canceled my contracts October 2014 when they expired.December i saw that Cell c was still debiting money so i phoned customer care again and canceled AGAIN. Then February 2015 Cell c was still debiting money so i went to a shop and asked to cancel it there AGAIN for the 3rd time . The gentlemen then asked me to wait because he had to phone customer care to cancel the contracts and they would want to speak to me. I then spoke to the guy from customer care and explained to him that this will be the 3rd time canceling my contracts.He then with a rude voice asked me who i spoke to and from what number i phoned and exactly when i phoned. This was 4 months back.How should i remember??? After saying to him that i cant remember from what number i phoned and that i could only say i phoned from my office land line and i can only say that it was October he kept on asking exactly when.He was so rude it was as if he wanted to say to me that i **** about phoning. I phoned and canceled the contracts after they expired. Why would i keep them if i didnt even use them when it was still active??? Worst service provider ever. Also i want to know what about the money they stole after i canceled?