Billed for a service cancelled over a year ago

I am angered by the *********** staff of Cell C. I called the call centre retentions/ cancellations 084 143 department (July 2016) to cancel my TWO month to month contracts as i will be porting over to Telkom. They acknowledged my cancellation, months go by, they continue to bill me. They then refund me my money. But continue to bill me. Every month i have to instruct my banker to reverse these ******* debit orders. But next Cell C continues to bill. 1 and a half years later i am ****ed off i have to deal with these fools at Cell C that keep telling me i must call their legal department of which i cant get thru. Furthermore i need to first settle the outstanding amount before i can re-cancel. Have you ever heard such BS??? I must pay for a service that im not actually getting because I am actually on the Telkom network you dummies!!!!