IRS scam

Someone from 347-284-6596 called my cell phone 13 times today. Left a threatening message claiming to be from the IRS. Said that there are federal charges against me from the IRS and that unless I call them back I will be arrested on federal charges. The person who left the message identified himself as Doug Miller, but had a strong Indian accent. When I called back another person answered and said that he is not familiar with the case but told me that when Doug calls tomorrow I should really answer my phone. I think I will, because I want to know how much money they want to scam from me, then I'll report the scam to authorities.