Who called from 3606801230

Auto call. voice message says IRS suing me and to call number. 2 calls in 2 days totally different numbers

This started happening a year ago, stopped for a few months, and has now started back up again. I get at least 1 call a week from the following number asking me to call back immediately: 3606801230. I know this is an IRS scam. How do I get them to stop!?