Cancellation process is painful.

I have cancelled with Mix Telematics August 2021, they since debited my account in November December and i have now received a January invoice/statement. I have also tried calling them but when i get through to someone they transfer my call and then it ends with a Leave a message and a consultant will call you back?? I am still waiting for the consultant to call me back. This is now ridiculous. I have also received a call from them confirming cancellation but also upselling to the current vehicle. I am paying for this service on a vehicle i don't have anymore???? This is now becoming annoying. I have so many case numbers as i have complained VIA email as well?? I need to be re-imbursed for my debits,