Failure to cancel contract costing me money

I chose to cancel my Cell C contract which was up for renewal in August 2017 since my financial status is such that I cannot afford this contract any longer, yet after many attempts to do this with the call center my bank account is still being debited by Cell C.

I resorted to going to a cell C store to sort out the problem since this is becoming a financial burden on me but after being assured that the contract has be terminated my bank account was once again debited by Cell C. This is unacceptable, you guys are basically *****ing from my account!