contract not cancelled correctly and debit order

I initially took out a contract with Telkom, the P8 lite, Because the phone was not available in white, The contract was put through in another colour by the sales associate. A few days later the phone was ready for pick up and I had received the white phone. So the sales associate had to make a cancellation on the first contract she had sent through with the different colour. Throughout the month of October I was in continuous contact with a lady from the call centre in which she was trying to cancel this contract which has been on my name since September. I have also gone to a Telkom store to enquire about the cancellation many times. This month I received an email and an sms saying that R3647.98 will be debited from my account. This is unacceptable for a phone that I never had and that amount should not be debited! I want an immediate cancellation on the phone that I currently do not have.