No notification of faulty tracking device

Discovery Insure are quick to advertise rewards for driving well, but their client services are poor. My vehicle's tracking device stopped working after being replaced 2 months prior. I did not receive any notification that the device had stopped - I had to check myself after a week and a half of no activity on my Vitality Drive. This is now the 2nd time this has happened in the space of 3 months. You would expect to be notified about a fault in a device that is used to monitor your vehicle for accidents and potential hijackings - yet when confronted, they refer you to their terms and conditions (which is listed under their FAQs, and just informs you on how to perform these tests).

I need to seriously reconsider this insurer - what is more important to me? Rewards and cash-back, or safety and peace of mind and good client services?