I too, received a call from this number.  They left a message on my VM.  Their name now only says C. Martin.  Telling me I should call back or (in other words) face dire consequences with the treasury of the US.  In any case, I blocked my number (*67) and called it back.  It immediately gave a recording it was not available and to call back later.  However, I suspected that since I had my number blocked (*67) it was programmed to give that message but when I tried the number again without my number blocked it still connected quickly and a recorded message saying the number was not available and to call back later.  Should anyone (like myself) who gets this call with names (C. Martin) and phone numbers to call back report this like the other posts indicate?  I will but my guess is these folks purchase phone numbers to make the calls  to threaten people and then after a day or so, buy another number and ditch the number they called from.  Any suggestions?  Who do I call to report this?
My husband (who is originally from India) caught their accent on a call identical to this one last year....so it is not like this just started; it's been going on for a while.  Hopefully, these folks do not prosper from someone that just doesn't know they are a scam.  I am concerned for especially seniors....they are the most vulnerable!