Faulty Tracking device fitted and no Help

A faulty tracking device has been fitted to my Vehicle, and despite various calls by me to then including Reference numbers received from Netstar fail to respond since Mid January 2018. I was made aware of this faulty device by Netstar on a number of occasions when they phoned my advising me that they have received distress signals from the unit without me activating it, I have spoken to Netstar service department each time the have contacted me regarding these faulty signals and even got a reference number CAS- ********** -F8RO from them to have the vehicle booked in. I have also refused to have the vehicle and system serviced by a certain branch because of the previous device that was faulty and they could not help me ! giving me stupid explanations that the (cold) weather was influencing the tracking unit This is pathetic service and my next step will be to seek legal advice for breach of contract