Non functioning vehicle tracking sytem

Its happening for the second time that my vehicle cannot be tracked by this service provider - Netstar - Cyber sleuth. My land Rover bought in 2010 was fitted with is device only to learn 3 years later that is was not working and they could not even trace my vehicle. I replaced the vehicle in 2013 and the same device was fitted. I used to check it once in a while until recentky when I learnt that the last ime it could pick the location of my vehicle was in October 2014. So for more than a year I have been paying for service that did not exist.