Unable to cancell my account

I requested an early termination of the only Cell C account I ever had. Paid the early termination fee on the 8th of May at 14:00. Emailed proof of payment to Cell C customer services, proof of payment address, with my account number attached, but never got any follow up calls to confirm and billing for this account continued. After several calls and hours of frustrating explanations, I happened to speak to a call center agent who promised to sort this out. Again proof of payments were sent without any luck. 6 months later the contract technically has come to an end in October and I am still being billed on top of having paid an early cancellation fee. Cell C store at my local mall provided me with a Case number, but indicated that I would have to go back to the call center as they would just be go betweens. I demand a refund for all the months I paid for an account that was not closed due to inefficiency on CELL C's side. I demand an apology for all the time I have spent to resolve this and I promise that I will NEVER NEVER EVER take out any CELL C contract or purchase any of your products for my self or any of my staff. All round the experience has been very frustrating and very poor service from everyone involved. I am being kind not mentioning names and specifics as I have a full record of all my interactions with all involved. Case number ********** 794 needs to be resolved and monies ****** out of my bank account refunded