Contract Cancellation Request - Consumer Complaint for Vodacom - Head Office

For the past two months I have called the Cancellation Department requesting for my contract to be canceled and the number to be switched to prepaid. It should be noted that my contract expired on 1 November 2020. To date, all the Call Centre Agents have sent me from pillar to post, refusing to adhere to my request. Every time I call, they promise that my request has been processed only to find out later that has not been the case. So how many times should I call the Cancellation Department before my request can be taken seriously?