CONTRACT NOT CANCELED

I was involved in a car accident in February 2022 the car was written off, my contract with Cartrack ended in April 2022. They have been debiting my account all this while, I have informed them that I do not have the car any longer however I keep getting calls from them and they are still billing me. I sent an email two ago informing them to cancel my contract they did not respond, I phoned the same day I sent the email and I was informed that my contract will be cancelled. I sent an email again a few days later still no response, however I keep getting calls because I had to stop the debit orders. Why am I being billed for something that I do not have,I have phoned and sent emails however they are still demanding money however they do not respond to my emails. Their service is very poor I hope after this review they will cancel my contract and stop harrasing me.