It's a Telemarketer. They use a dialer and have called my phone constantly on a Sunday.

It's a robodialer.  Got a call today at 7:10pm

This is a criminal scam. They call from different numbers (including different area codes). Google cannot find a commercial company with any of the numbers.

Caller ID shows "Insurance SRVC".

Just hangs up, no message.

They call us daily, sometimes twice.  Prior, caller ID read :Insurance SRVC, now it just lists the number.  They never leave a message, just hang up on the answering machine.  It is very annoying as it has been going on for months daily.  I don't want to answer b/c if they hear a human's voice, it could trigger more calls.  I need to figure out how to block them.