Tracker ****in uselessssss

Ok i drive a ford ranger 2016 model. So i took insurance trough momentum and they advise me to Use Tracker south africa. I never ever had any problems with my Ranger. So approx 2 weeks after installation i drove for an interview stopped the ranger and when i wanted to start it. Dead. No battery. So o checked. The negative battery earth was comoletely loose. I made it start. After 4 weeks my vehicle was dead all battery gone had to jump start several times the whole battery was done for i replaced it R1700 the battery only stored 258 when it suppose to store 750. Ohms. I called them they changed this and changed that. Now i want it rwmoved and i refuse to pay 1 sent towards the contract and they tell me i should phone head office. I am not phoning anyone. They must come and rwmove this piece of **** device ASAP. ****in useless.