IRS Scammers. I call them back, and after chatting for a couple seconds (no personal info shared) I conference in a third call that plays Rick Astley's Never Gonna Give You Up. After 6-7 times they stopped answering my calls :).
They've been calling my mother all day threatening her, saying she owes the IRS money and if she doesn't pay today, she's going to jail if she doesn't pay. They said she's been at her home already trying to bring her in. Total [***] and liars! Please don't fall for this