Failure to cancel my subscription

I called Multichoice in May 2023 to cancel my subscription, and the agent confirmed the cancellation. However, on 11 Jan 2024, I received a call from Black Associate stating that my account had been handed over due to non-payment. I immediately contacted Multichoice for confirmation and a copy of the call where I cancelled my account, but I have not received any feedback or resolution from them. Black Associate continues to call me regarding payment arrangements. I have advised them to listen to the May 2023 call to confirm the cancellation.