Tracker not working

I should be giving Netstar 5 stars but i am really not happy with the poor service they've just rendered. i upgraded my tracker and a technician was sent to install but it was still a problem to track my car on the app. i escalated the matter on the app and netstar sent me an email that the issue has been escalated to IT. after two days i called them with my airtime and the lady i spoke to said it has been escalated she will call on Monday to follow up. on Monday the lady never called. i called Netsar gain on tuesday with my own airtime and i spoke to a gentleman who apologised on behalf of the lady and he told me that the tracker installed is not picking up any signal even on their side they cant track where the vehicle is. The gentleman said he will escalate and request for a technician to come and take a look at the tracker installed. I was told that Netstar will call me back before friday and make an arrangement for the technician to come and take a look at the device. Today it is thursday and netsar has never called me. i am still sitting with a faulty device. if my car gets ****** how are they even going to tack it, i am really frustrated here. Please help.