Vodacom contract issue!

I was shocked by Vodacom's response when I contacted them regarding a cancelled contract that somehow was reinstated without my approval after over 4 years. Suddenly i received an invoice and because my bank details had not changed, they collected what they believed was due. I was told I had to go through the cancellation process again:( and at least 2 more payments would be processed. As this was without my approval, why should I have to do anything. All the Call Centre staff checked the records and confirmed the cancellation is on record. No apologies just had to accept the process of converting from contract to prepaid but still getting statements for a contract that was cancelled OVER 4 years ago. Tried asking about refunding the R1111.14 that was taken *****ulently and was told "Good Luck" with that. Surely Vodacom's reputation doesn't mean much to them if they treat customers like this - they should own up to the error and refund me with interest!