Same here
Leave a voice message, called back. They have my address, and state I own tax. But cannot provide any legal document. I have also got similar voice mail from caller id of Seattle and Santigo. I will block them all.
I called the number back for the IRS scam. Talked to the guy for a long time. He finally admitted it was a scam and that he even felt bad about it. Said most people realize it is a scam but a few fall for it. Says he does it because no other work in the area that he can do. Would not tell me exactly where he was but got an impression (probably Oman or nearby). But like I said, he actually admitted it was a scam after we talked for a while so don't fall for it. Let your friends/family know since it is mostly the elderly that are victims.