Bad service and bullying

Last year march/April my car a unit tracker was installed after 2days the car could not start, dealership took it back and discovered that the unit tracker is faulty, I informed car track nothing was done I could not even. See my car and more on the app it says I am. In gauteng that time I am in rustenburg, my phone was traffered from 1 person to another I even asked for cancellation June because I didn't receive any service, now money is being demanded from got a also a letter stating I will be black and listed question is how do a pay a company that damaged my car no one took accountability