Poor service from Netstar

I am sick and tired of Netstar and its empty promises, my cars tracking system lost signal on 11/06 and every days I am sending messages on the app via the health check portal, I start getting calls 10 days later saying they will send somebody out to fix it, and then get called by the technician saying he is coming, till this day 25/06 no one has come to sort this piece of ******* out. This will be the 5th unit they putting in my car and Im wondering if Netstar will ever get it right. They refuse to give me my money back and let me go to a competitor.