Unauthorised upgrade and issues for cancellation

I have had a 24 month contract with vodacom which has been paid in full till the last month of payment which was September 2023. I then was contacted by a agent from REWARDSCO letting me know that my sim can be upgraded to extra minutes and data at the same price which i have told the agent that I'm not interested at the moment.. At the end of October my bank account has been debited without me agreeing to any type of contract or renewal.. Have been sending vodacom e mails and trying to call them and i have even been to there store at gateway mall and was told that i need to pay the outstanding amount and a penalty to cancel the contract which i never agreed to and has been given the run around with no help whatsoever. I'm really having a problem to cancel the contract and i am being debited every month for a contract i don't need nor want.. Please help