What happened to TCF at Cell C

I called Cell C twice to cancel my contract with them, the funny thing they have been deducting from my account and i don't even use them as my service provider anymore . the last person I talk to said she can't help me because my account has been handed over for only R240 that i can afford on the other side they debiting my account. the person I spoke said will get a call back within 48 hrs it is now a month and I still see a deduction from my account. every time when i call no one reverts back to me, I requested the calls for my interaction with them still no action, so what's the next step. Is this company taking my money by force? Is this treating customers fairly.