Unknown caller, but NOMOROBO.com caught it and my telephone only rang once.  I signed up last night after reading an article.  The FCC had a challenge out to private industry to help with the huge increase of unwanted, illegal robocalls.  Nomorobo was on of the top award winners, and it is free.

I tried to file a formal, online complaint, but the sites are shut down due to the President and Congress being a bunch of lame idiots (Republicans AND Democrats....in fact, all politicians).

The FCC recommends that you answer robocalls, but hang up, and NEVER press a number to be taken off the list.  Talking to a human can also work, but it can be frustrating too.  Most of the humans you talk to cannot get a job anywhere else and work on commission only - including non-profits.