Vodacom Cancellation drama

I cancelled and paid a settlement amount on my Vodacom contract in Oct 2021. Everyday I receive calls from Vodacom saying I owe them an amount for the month of Nov 2021. I have explained to 10 different advisors that this is incorrect and that they should fix it. However there is still people calling every day. They have told me to email this person then that department but nothing is being fixed on my account. They also cannot provide me with the call I made to cancel this contract.

This is ridiculous and frustrating been going back and forth for a whole month try to sort it out