This number left me the following automated message:
"... from investigation department of federal government. We have just received a notification regarding your tax filing ... from the headquarters of IRS which will get expired in the next 24 working hours.
And once it get expired, after that you will get taken custody by the federal officers, as there are for serious allegations pressed on your name. At this moment, we would request you to get back to us, so that we can discuss about this case, before taking any legal action against you.
The number to reach us on a 615-625-0104. I repeat, 615-625-0104. Thank you."