Cell C not cancelling contract and keep on charging me!!!!

I cancelled my contract via 084143 in July this year (Contract expired 22 August). Yet every month after that they are still charging me. I emailed October and November, yet still no response. I phoned again today, and now they are saying they will cancel on the 12th of November, and I will still be billed!!!! I want my money back for the past 3 months!!!!!! and I want this cancelled immediately!!!!!!