Unauthorized debit after cancellation

I canceled my contract in January 2026 after a year with onair I realized that the agent gave out misleading information. They told me it's a 12 months contract and I will not have to pay Dstv. I returned the box after they listened to the call and confirmed that I was mislead. To this day after 8 months they still debit my account even after they canceled the contract and collected their box. I have stopped the debit order but they still debit unauthorized. This is abuse of power and I will definitely look for further assistance with this else where.