Wrong Billing

One of my contracts were ending in July, so as per Cell c procedure, one needs to cancel their contract a month before the contract ends. So i sent email requesting that, only to find out that the person who was attending to my request, cancelled the wrong number and i was forced to pay an ridiculous amount, i was not advised about. i called cell c to inquire about the cancellation, i was told i need to pay a settlement amount for both accounts and the ridiculous amount they debited from my account, was not reflecting on my account with them. i paid the settlement amounts and i was told there would an invoice i would need to pay at the end of sept, and i agreed to it. so end of sept no invoice money was debited from my account, and thought everything was in order. so now i am getting calls from cell c telling me i owe them that ridiculous amount, the amount they couldnt see before i reversed it. cell c staff were careless doing their jobs and now i have to pay the mistakes their did. no body there is willing to assist, everytime someone calls me i have repeat my story, and when the call ends i am told it will be sorted out, but nothing is done, i am instead being called to be told i owe monies i know nothing about. Hello Peter please assist me, as i am not up to see my name listed on ITC for the negligence of the cell c staff. i have the emails i sent to them when all this started, and phone records cell c should have. thanks