Vodacom's failure to cancel a contract which has ended

I have a contract with Vodacom which ended on the 08 November 2020, I called on the 31 October 2020 where i lodged my 1 month notice in which i stated my intention to cancel the contract. I was told that the contract will be cancelled by the 30 November 2020. To my surprise on the 1 December 2020, Vodacom still continued to load my contract package on my number instead of converting it to prepaid.

I then called the cancellation department, they said told me they escalated the matter and the issue was to be resolved before end of business of the following day (02 December 2020). I called again on Tuesday to ask how far was the process of cancelling my contract, they told me they were escalating the matter and it was to be resolved. I called again today (3 December 2020) and still they told me about the escalation. This is really frustrating as they will still debit my account for a contract i cancelled.

All i need is for Vodacom to cancel my contract, so that i can port my number to another mobile operator that will serve my needs better.