I e-mail the ftc and lodged a complaint...everyone should do the same--it is unlawful to impersonate an IRS official...at least I would assume so...email: www.ftc.gov; click on "complaints" then follow the script....
The catch 22 with this IRS scam is that the calls are from overseas and that makes next to impossible to take sort of action against these telemaggoters. Thankfully the majority of our nonsense calls are automatically blocked.
Consider the option of a call blocking device or app.
Good luck to one and all.