Telkom mobile failure to terminate contract

I have had a mobile contract with Telkom mobile for the last 6 years ,my contract reached renewal in September this year and I decided to convert to prepaid. I called Telkom mobile to do this in September and the agent told me the account was converted to prepaid.

I had to cancel the insurance separately which I also did and got a ref number from the insurance but telkom didn't give any reference.

I have still been debited by telkom and had a case escalated by their department which still hasn't been resolved ,they have disabled my Sim card after being told specifically that the number needs to be converted to prepaid, do not ever sign up for a mobile contract with telkom ,they are incapable of following instructions and will take your money regardless of whether you have terminated your contract