Yep, the big IRS scam.  Glad you didn't fall for it.  My neighbor got a similar call from a different number and they told him they would be at his house within an hour to arrest him.  He asked them if they could get there sooner cause his mother-in-law was coming over and he'd like to be gone before she gets there.  :-) Here's the real IRS and Forbes Magazines info on the scam.
https://www.irs.gov/uac/newsroom/irs-repeats-warning-about-phone-scams
http://www.forbes.com/sites/johnwasik/2016/06 ... u/#6cb8a18e171f