Forced into a contract for a car I do not have

So I had a ranger wildtrack and because they deemed it a hot car they forced me to get a tracker otherwise they would not cover me for theft. I get the tracker through Netstar via Budget. Remember I wanted none of this. A few months later I sell the car, the lady at budget when I cancel the insurance says its fine, as long as I have a remaining car left then it should be ok. I then start getting billed from netstar for a car i no longer have. I try calling into them but never get through as the wait is often longer than 20 min. I send Budget and Netstar two emails with no response from either of them? Now I keep getting multiple debt collecting calls for a tracker on a car I no longer have or have insurance on. Im going to log a complaint with the consumber goods ombud and the inssurance ombud.