Poor service when cancelling the contract.

We made use of Supersonic at Duncan Court in 2022 and 2023. On 28 November 2023 I gave notice to them for cancellation, which they acknowledged. In January 2024, another debitorder went off my account. Now they are threatening us with legal action because there is another outstanding amount. Very bad after sales service when cancelling the service. They need to be reported to the Consumer Ombud. I phoned today and after holding on for 8 minutes were cut off. I have send numerous emails with limited and no response received back.