Constant faulty equipment from netstar

I would like to address some concerns regarding the Netstar tracker and its recent effects on my bikes and business. I am contracted to continue this relationship for the next three years. My trackers have been replaced multiple times, yet I continue to encounter issues with their effectiveness. For example, the tracker on one of my bikes has not worked since June 18th, but I am still required to pay the monthly instalment for a service that I cannot use. Cancelling would also have adverse consequences for me.