Just called.  I didn't answer.  No message.  Caller ID read Unavailable.  Well, so was I!

Has called 6 times in 3 days.  CID says UNAVAILABLE and the number.  I let the machine answer, but they never leave a msg.

3 calls in about 24 hours so I answered.  Lady knew my name and asked about age of house, etc (which I ignored).  Then started in with home upgrade pitch.  I said I wasn't interested and she disconnected before I could ask to be removed from their list.  Now blocked.
By the way, I called back to see if it was a real number and got a lame recording (with tones and all, made to sound like official phone co message) that my call did not go through, call back later...

Called me today.

BLOCKED, thanks to your posts.

Two calls this AM -11:22 and  9:20. They don't leave a message.  I maintain a practice of not answering the phone from a company called "Unavailable'!