Cartrack endless frustration

Good day, I had a cartrack unit fitted in my car for insurance purposes. Ever since the unit was fitted my car worked for 3 days and then refused to start. I had an auto electrian look at my car and found out I need to change my ignition and get a new key. The car worked for less than 20 minutes and cut off completely, cartrack hasn't even contacted me to say something is wrong. I got the insurance to tow me home, I contacted cartrack and they said I must pay R750 for them to come and check the unit. Why must I pay for something when I pay a service fee every month and to this day they still haven't contacted me. I have repaired my alternator and still the car refused to work, the unit keeps draining my battery. Yesterday I put in a brand new battery and still have the same problem, my battery got drained out. My car worked perfectly fine before the device was installed, ever since the unit was fitted I never got to drive my car. Please resolve this issue without additional cost even if you just take your unit out. I would further like to mention that I have a all the receipts for the repairs done to my car.