Same thing happened to me. I got a VM that said to call back immediately. Then I called back and some guy with thick Indian accent answered "Hello IRS, can I help you." After some quick back and forth, he became frustrated that I was asking for his manager and what division within IRS he worked in. He actually yelled at me, saying "Stop it, I am working in IRS." At which point I hung up. A$$holes!
Issue at hand is extremely time sensitive. My Officer Julie Smith from Internal Revenue Service and the hotline to my division is 415-926-4147. I repeat it's 415-926-4147. Don't disregard this message and do return the call before we take any action against you. Goodbye and take care.
Its a scam as far as I know the IRS will not call you, don't fall it! They will try and trick you! IRS will only contact you by mail! Do not send them any money! Sounds also like false representation of a officer! Contact - FTC, A.G., Local law enforcement.