Impossible to cancel and close Vodacom contract. Still paying for nothing.

I have an account with 2 contracts and mobile numbers. One of them has not been in use for over a year and a half. It has no phone associated to it that needed to be paid off. Since early 2024 I have tried to cancel the one account, with no success. I followed the steps online to cancel it. The last message I received was an sms from 6 March 2024 stating "You will receive an SMS and Email with your exact cancellation or conversion date. Until such time, your Vodacom Contract Cancellation is not confirmed." I am finding it impossible to close this contract and Vodacom keeps billing me R260.99 every month.