Also contacted the Federal Trade Commission at https://www.ftccomplaintassistant.gov/GettingStarted?NextQID=216&Selected=t#crnt
and the scammer's telephone number was disabled. I hope they prosecute!
IRS scammer. Not too bright. I asked him for his Federal Agent Number and how much do I owe. The number he provided was EIS5501. I have contacted the IRS at phishing@IRS.gov and the Feds, who will shut his operation down shortly, at https://www.treasury.gov/tigta/.