Who called from 2137255678

I have 2 phone numbers on the same line, one is for my fax machine. This numbers has called my fax 5 times today and Ihave tried to call them back to ask them not to call me again. When I call, I get an answering machine saying to press any number to be removed, still get calls several times everyday.

This number started calling this week.  Today twice already,  no message.  Phone ID shows Los Angeles, CA.  Let them try..  Scam?