Cancelled Contract and still being billed

Months ago I cancelled my 8ta contract, the amazing 10GB for R199 a month. Due to the contract being throttled so badly that I could not use it. <br> <br> I suppose that they wanted people to get of the contract hence the poor download speed on my contract, surprisingly my Telkom mobile sim cards worked 100% in the same area. <br> <br> I have thus cancelled my contract at Telkom stores in South Gate months ago an I am still being billed for it?<br> <br> I do not even have the sim card, this contract needs to be cancelled and all the extra money paid to your account needs to be reimbursed.<br>