Policy amended without my concern

I had a tracking device in my vehicle done my Telematrix. They amend you contract as they wish and without your consent and you just need to keep paying. Very rude call center personnel that does not assist you in resolving the issue. They also very slow in answering phone calls. What happens the day they ***** your vehicle? How long do you need to wait for them to answer your call? Rather choose Netstar or Tracker.