Same thing the other guy said. An IRS SCAM. They try to get you to call a number that is rigged to accept pay-per-minute calls. DO NOT CALL THAT NUMBER! If you do, your phone may be billed up to $2500 per minute! so be careful! ; )
answer was as a Representative from IRS to do investigation
when I told them that they are fraud and their number on internet all over person reply was : do you want to catch me