Who called from 3602030029

I have received two calls w/voicemails from it.  The calls originate from Folks, WA.  They identify themselves as some kind of enforcement for the IRS.  They have a foreign accent and answered the phone when I called them back at 5:40 AM Pacific Standard time.  Seems very off that a gov't employee is at work at 5:40 AM Pacific time. They answered the call when I called back but would not answer any of my questions (more suspicion)...

Caller identified as US Treasury and can help to get persons out of trouble

Caller left a msg.  With broken English he says he is with the US Treasury and ignoring the call could lead to  prosecution.  My understanding is the US Treasury does not call anyone and would send a notice by mail if there was a need to contact you.

2nd call within 1/2 hour. First one from 9172017579. Same message, this one had better English but still bad accent.

Same message - different caller "Kevin" and different number than the first one which was a few hours before.  this is crazy!