Apparently Netstar is not responsible for notifying me if the tracker stops working

My tracker stopped working 17/02/2021 as per their system, no one bothered to notify me of this. l have been paying for something thats not working. and when l discovered that its not working l call them l was told that am supposed to call every 6 months to check if the tracker is working, that Netstar is not responsible for notifying me if the tracker stops working, then what am l paying for?