Deducting money that I am not responsible for

This is my second or third complaint for them and this is going on for about two years. Nobody can give answers for the money that has been deducted from my account. Somebody has contacted me from the head office and he said he will come back to me, till now more than 6months ago still nobody has responded. I will defintely never even do business with them again or recommend them to anybody. Please be careful of them and Cell C because they deduct huge amount of money from your bank acc and give no explanation. POOR SERVICE