This is definitely a scam call. Plug this number into 880notes.com or scamcallfighters.com and you will find MULTIPLE reports, as well as valid information about how the IRS NEVER makes cold calls or threatens individuals about tax discrepencies. The caller's recorded message says that ignoring his request to call back is a deliberate attempt to avoid appearing before a magistrate. Now think about it. First, if there was really any legal problem, you would be advised by mail, specifying the reason for the complaint as well as the identity of who was bringing it. No real agency would ever use a RECORDED call, that would not identify you by name or fail to give you any details.
We are smarter than these people think we are.