Billing and expiry unit.

Hi My tracking device has expired in January 2018, an agent called me last month saying im due for an upgrade and that i will be paying R199 and a technician will call me to arrange installation. Till this day no one has called but my account has been debited as usual. Another thing the current tracking device hasn't been working properly as the alarm will go unexpected and when i press the remote it doesn't respond and im surprised no one from the Nestar has attempted to call me and found out if my vehicle is safe? This tells me that they don't care about the safety of my vehicle but only care about debiting my account. Im really considering moving my tracker to another company as Nestar don't really care about their customers.