BEWARE CELL C SPECIAL DEALS

I was offered a "SPECIAL DEAL" by Cell C when I was contacted by a Cell C tele-marketer. He in informed my contract was expiring, but I told him I'm going to cancel my contract because I can get a better deal from another company. He then offered me this "SPECIAL DEAL". I signed the contract BUT Cell C did not honour the deal, they keep on taking higher amounts from my bank account. I have sent numerous e-mails, spoken to the accounts dept. THEY DO NOT LISTEN!!!!! I WILL NEVER, UNDER ANY SURCEMSTANCE, EVER DO BUSINESS WITH CELL C AGAIN.