Bad service received from CellC

I cancelled my contract with Cell C in Feb and was very specific that no debit order must be put thru cause I will be on prepaid. But the debit order was put thru ar the end of Feb. I returned it and at the end of March they still deducted double debit order. When I call them I never get anyone to assist. What they do is to try and call and if you dont answer the close the case. It happens that you are nowhere near your phone or you are in a meeting and unable to answer the phone. There was a very rude woman called Simphiwe who has no client etiquette, her attitude is set on infuriating the client and also make threats and not to assist. My blood was very high after talking to her that I had to go see a Dr after speaking to her. That is one person that must never work in a call centre, let alone deal with customers cause she is very rude