Contract Cancellation

My contract with Vodacom expired on 16 December 2020 and I have being trying to cancel it with Vodacom but no luck as I am still struggling to date. I have called the *** number more than five times and asked that they move my cellphone numbers to pre-paid but not even one of the consultants managed to cancel the contract. I do not think Vodacom want to cancel the contract but to force me to have a contract against my will.