I got the same message many people have received at 213-336-3228: "This call is extremely time sensitive, office of Heather Gray at IRS. Hotline to my division is 213-336-3236. Don't disregard this message. Do return the call before we take any action against you. Good bye & take care." The IRS never calls people. This is a scam.
I got a call from this same number and the same message. I called back because they have called me before and hung up on me. Told the man that this was not the IRS and he asked me how did I know. i told him by the way he answered the phone. I told him I know this is a scam and to please stop calling me. He called me a [***]. The he told me to go [***] myself. I told him I think maybe he's been doing too much of that himself and hung up. I have had them call me before with the same message with a different number.