I received the same call. A woman was telling me that I have a warrant if I did not response back, this will count against me.

Should I be worrying about this?

I have received two calls from this number. The woman had an Asian accent and claimed to be with the investigative branch of the IRS. If I didn't call back I would be arrested. The second time she harassed my roommate and told her if I didn't call back she would send the cops to my work place.

After receiving a call from this number I decided to look it up and seeing that people said it was a call from the IRS I decided to wait for another call and it happened.  She said she was from the IRS and I told her I did not believe her and when I said that she said "if you do not believe I am from the IRS the go F*** yourself.  How is that for customer service

What you should be worrying about is how you are almost gullible enough to believe this is real. Google IRS SCAM and learn to protect yourself. For that matter, Google PHONE SCAMS and spend the day reading about how bad it's gotten and why you should never answer calls from unknown numbers and why you should never call back an unknown number.

Really? What kind of service do you expect from a criminal who cares nothing for you other than trying to get your money? It's not "customer service" it's "scam service," and it's exactly what you should expect if you call back or answer a number you know to belong to a scammer..