Vodacom doesn’t like cancellation of contracts

In 2022 I requested an early cancellation for my contract since I was no longer working. I paid it up and emailed their cancellation department with a signed quotation, proof of payment and my copy of ID. They did not cancel my contract and have been debiting my account since. When I call they give me a run around and they never investigate anything. I’ve been calling to get my contract cancelled but what about the money they have been deducting?