Upset vodacom customer

I cancelled my contract on the 27th of March 2024 at around 11:am and recieved the confirmation email to say my contract has been successfully cancelled. Later that day around 17:00pm the same number that had been cancelled was upgraded, no one called me nor did I call in to change my decision of cancelling. I have been calling every week from that time and all they tell me is that they have escalated the query and the back office will be responsible for reversing the upgrade and canceling the contract. But now it's almost month end and no one has contacted me from the back office. Because the cancellation of the contract should happen from the 30th of April 2024. It was not in my budget to have a debit order on my account for end of April because the back office is not able to assist me.