incorrect billing

Can't begin to explain how dissatisfied I am with cell I had a contract with them which I was paying 169 in February I called asked them to cancel my contract and they gave me a settlement amount of 978 which I settled in full and they said that the contract has been cancelled, in march they debit me 978 I logged a complaint and skhumbuso ndlovhu contacted me and apologised and said that I was incorrectly charged but to my suprise cell c is still debit me 978 whenever they feel like I work in the financial sector and I know very well that what they are doing its ******* and against Cpa, I'm gonna take legal action against cell c because I reverse their debit order every month and some times I even had to pay penalty charges as the was no money when they debited me, I swear I'm gonna take this further