Hi,
They just called me too, from that same number. They provided me a "case" number which I wrote down, and I listened as the lady told me I was seen as suspicious of violating an act of legislature, but she only stated a title and no legislature number or law reference number, so when I asked her for the number of which I was suspicious of, she hung up on me. This is a scam.
The guy said he is calling from Federal investigation of IRS, and they already sent me this this and that notifications. Totally fake. They keep calling me from different phone numbers. Is there a way to stop them?
They called me too saying they were the investigating arm of the IRS and police would be at my home in 30 minutes to arrest me! They must think I just fell off a turnip truck! I called the number back, someone answered and I told them I would find them and am reporting them to the IRS, FBI, FCC and Interpol [I suspect they are out of the country]. They hung up rather quickly.