I got message from them too and it looks like a scam a lot of people reported.  I hope they get nailed too,  its very stressing to get these kind of phone calls.  Thanks to people reporting this!!!!!

This is a Con scheme using IRS name.
When I got a call from this number (415) 251-2995, my caller ID showed that the call was made from NAVATO California, but the number (415) is San Francisco area code.
Message they left stated that my Tax Return has a major error which will harm me financially, legally and all the bad things will happen to me if I don't fix it right away, even FBI will come to arrest me if I don't fix it etc......
I called the number back and a woman answered the call stating that she is an IRS agent and there was a lot of noise in the back ground to make me believe that she was in a big office with bunch of other agents. I asked her, "where are you located? are you located in Novato California because my called ID you called from shows that, where are you located?" Then she said "it doesn't matter" and she hung up the phone (I think she realized that I knew she was a Con Artist). I called the number again and this time a message said "the user who you are trying to reach is not available", I called the number again 5 min later and all I got was a busy signal. Then I called again and this time a woman named Michelle answered the phone saying, "Hi, my name is Michelle and I am IRS agent" I said "hi Michele, you Con Artist, I know what you are, you are going to jail doing this" she hung up the phone..... I called the number again and this time the call did not go anywhere, it didn't even ring. I called the number agin and this time it rung three times and it stopped ringing. Try calling this number just for the fun of it and threaten them, make them feel soooo bad that they will not want to do this any longer.

“City of high(?) officer Heather grey(?) from Internal Revenue Service and the hotline to my division is 4152512995. I repeat it's 4152512995. Don't disregard this message and do return the call before we take any legal allegation against you. Goodbye and take care.”

.Total fraud that I have been hearing about But I never thought I would get the call. Here is the exact copy and paste from my voice message.

Here is the mesage they left me. “City of high(?) officer Heather grey(?) from Internal Revenue Service and the hotline to my division is 4152512995. I repeat it's 4152512995. Don't disregard this message and do return the call before we take any legal allegation against you. Goodbye and take care.”