I called this number back, and it's a local air conditioning & heating place, (Mountain view, CA) so I blocked it on my phone, and on Comcast, by dialing *60.

Thanks for an informative post.

"Missed Call" in Google Voice - means they hung up as soon as they heard the "challenge" message. If they call again, will block.

A recorded short message, then hung up.  REcieved multiple times.
Called number, got only a recorded message about heating and airconditioning. No company called, but clained they'd be in the area
I'm on the do not call list and have never contacted a heating airconditioning compnay,
On second call - very noise line said it was "gofundme.com'

Same problem, called hung up, dialed them ... boiler room claiming to be gofundme.com ... or was that gofuckme.com
Very noise line.
Called ATT.  This number 650-265-2319 is an AT&T landline.  No help at all ... which is expected, but had some time to try.  Perhaps if they had more complaints that would cost there service calls time they may someday take action.
Suspect this is a local landline connected by VoIP to an India boiler room