This is an IRS Scam, threatening to get you arrested if you don't return the call and follow their instructions.

told to return call to IRS so as not to be arrested and brought before a magistrate judge.

I got a recorded message from this number (no caller ID showed for me, but I was told to call this number back).  The female voice said something to do with serious attention and final attempt to reach to avoid appearing before a magistrate or grand jury on a federal criminal offense. She said to know the case # or speak to a federal agent to call the number above.

They called twice telling us the sheriff was going to come arrest us if we didn't call this number and that there was a lawsuit against us

They called us with the same massage.