No, they are not!!! Don't give any information to them!!! They are f*&%^$g as#$&^#es trying to make easy money!!! I already submit a claim on Federal Trade Commission.
You're the victim of a scammer - if you sent your money by Green Dot money pak - it's gone! Report the call to the IRS, the FTC and the FBI.
You're new to the US but one thing you need to remember - NEVER pay anyone who calls you and says you owe money, or threatens you. Anyone could call and say you owe money/are being sued. You always demand documentation through the mail that proves what they are saying is true. If they can't or won't send you anything in the mail proving what they say is true, then they are scammers.
So sorry that you had to go through this. Welcome to America. :/
This scam has been going on for years. They always threaten you to "act quickly" because the more time you have to think about it, the more likely you'll see that it's a scam.
From NBC news:
http://www.nbcnews.com/id/42347772/ns/busines ... r/#.UgrjsHy9KSM
And your first contact from the IRS will always be written notice, not a phone call:
http://www.irs.gov/taxtopics/tc201.html
"Topic 201 - The Collection Process
If you do not pay in full when you file your tax return, you will receive written notice of the amount you owe, a bill. This bill starts the collection process, which continues until your account is satisfied or until the IRS may no longer legally collect the tax; for example, when the time period for collection has expired."
"The first notice you receive will be a letter that explains the balance due and demands payment in full. It will include the amount of the tax, plus any penalties and interest added to your unpaid balance from the date the tax was due. You may pay the amount due by sending the IRS a check or money order, payable to the United States Treasury, with a copy of the notice."
I made an assisted online search and it says this number belongs to IRS...I dunno what to do..feel like killing myself rather than facing the humiliation