Incompetence of cell c and its stuff.. And also the debit order department. I'm sick of this now

I have a contract with cell c since 2011 and they haven't been giving me problems. But recently in June I called Cell c and informed that that I'm canceling my contract in August of a wifi I don't want it to be renewed cause I'm getting another contract with them. So the *********** stuff didn't do there job but I mentioned early that I want to cancel previous contract and start a new one. I gave them the authorization to deduct from my account every month the amount we agreed on but then they do there own thing and then put the blame on me. Now they stopped my wifi can't use the data saying I'm in errors but they didn't deduct the amount we agreed on. Month end of November they deducted R1306 without saying anything and informing me and then I reversed it. When I call the consultant trying to find out what's happening she said she doesn't know cause on the system it says she owes August but I have no knowledge of owing them cause they deduct every month from my account. I've been with them for a while but now they treating me like nothing and I've been nothing but loyal to them. When I ask to check what's wrong the consultant says it doesn't show on her system. They starting to **** people and having ***** how come on the system nothing shows while I allowed them to deduct. Cellc is starting to **** people now and think they can get away with it.