Tracker - Incompetence

Tracker has been invoicing my account twice now after I have informed them that I sold the vehicle last year. I have spoken to every division possible. I had credit notes issued but still they send debits through my account. I am still waiting for a call back from the one department. I have emailed. I have phoned and been transferred from pillar to post. But no success. I have never come across a more *********** company. I will never recommend Tracker to anybody. I shudder to think what would happen if I had been hijacked with this ****py service!!