Account supposedly canceled yet debiting my account !!!!!

I canceled my contract with Cartrack last year September as I was selling my vehicle. I called them every month since September 2021 to cancel the contract and in December 2021 I finally got a cancellation letter however they still debit my account every month. Every time I call them they inform me they will listen to recordings to investigate why my account was not closed and why they still debiting my account. This is utter nonsense.