My client had the same type of call. When I called them back, he answered it "IRS", I asked for his name and agent ID #, which he did provide (Ray Miller 753211). I said I was calling on behalf of a client and he said the client must call him back and he hung up. I reported it to the Department of Treasury http://www.treasury.gov/tigta/contact_report_scam.shtml and to the IRS
[email protected].