Cell C - Extremely POOR SERVICE

I have a month to month data sim contract with cell c , I called in on the first week of Aug 2020 to cancel the sim & agreed to pay the Aug debit as it’s only fair. I noticed that I got debited again in September - I called the Cell C customer care and was informed the contract isn’t cancelled and there was no evidence of me calling .. I phoned in again today 12/10/2020 , Cell C advised that I will have to pay for October and November !!!!!!!!!!!!!!!! Which is obviously due to their poor communication from 1 department to the other ??? What is the point of calling into cancel a data sim etc if they won’t take the information and pass it on correctly !!!!!!!!!!

I don’t want to be paying for a sim I’m not using !!!!!