Im also from CO and they just called me, i listened to the whole message out of curiousity and called them back. I work for the gov. So i know that was no way to answer the phone, No introduction, name, title, Indian accent of course and is an absolute scam. Ask for paper copies to be sent through the mail if there is ever any questions.
Missed a call in the shower, called back. Same story, some Indian said he's the irs. Told him I didn't believe him. He said, if I don't think it's the irs, just hang up the call. I wished him luck with his scam then heard the robo voice mail drop.
Call from 323-899-8707 and left a message. like the others, claiming to be the IRS and that this was my final notice and the IRS was going to be filing a lawsuit against me. Left callback number as 323-899-8707. This is definitely a scam since the IRS does not work on the weekends, they always send you everything in writing since the government has to document everything they do in writing, and the letters always contain a claim number that YOU have to use to call them back with since they have thousands of cases they are working on at any one time. Any official government call will tell you their name, government office and location, claim number and official hours of business to contact them - they are not automated calls since they have to give you specific information about you and the reason they are calling.