The worst service experience EVER!!!!

I had two contracts with Cell C , one which I finished paying in May (well supposed to) . I called the call centre in April to make sure that the contract was cancelled after my last payment and the consultant confirmed that it would be cancelled and that I wouldn't be debited there after . Two months later my debit order continues ,I have called the call centre multiple times and they just refuse to help me . I've been to three Cell C stores asking for help and I left all three stores unsatisfied . I had requested for the recording of the call and it was sent to me . The store manager at Cell C Alberton city and I had listened to the recording of the call sent to me together and he agreed that the consultant that I had spoken to didn't do what they were supposed to . The manager called Cell C and spoke to a consultant , but they wouldn't even listen to what he was saying . The manager then promised to follow up on the matter and get back to me . I haven't heard anything from anyone since then and 5 months later Cell C still continues to debit my account . I don't know what else to do, this is so frustrating and every month I have to drive to the bank to reverse the debit order