It is Vivint Smart Home Security
You are either an emergency contact listed by someone that uses their service, or you use their service and are late paying your bill.  They have never called me other than to remind me a bill was due after my father passed away and it was his residence that the system was protecting.   A simple courtesy call letting  me know I overlooked paying them.    He had his bill payment set up through his bank account, now that he has passed away, I have taken over paying the bill and have missed paying it a couple times.  They will cancel his  contract with a death certificate, however we have kept it active since the home is not occupied.