Cell C refuse to cancel contracts despite customer not using their services

Cell C is a horrible network. On numerous occasions, I have tried to cancel my contracts. Written cancelation as well. No, I got an email to say, settle your account then we will cancel.. now they are letting that account which I have not used for 4 of my contracts run into thousands. This is sad huh, how do we survive. I have had two of the contracts which were never used in years and when I eventually cancel Allah too expensive I get told settling is the answer but my bill is running sky high. They are ******* in my opinion and they repeatedly try to debit my account for service I'm not receiving.