Caller ID said wireless caller.  Robo-call saying "Hello.  We have been trying to reach you.  This is the IRS",  That was when I hung up.  I've read about this scam.

Called 4/4/2016 at 7:52 AM and 11:50Am  and left a voicemail informing me that the IRS is filing suit and to call this number immediately. I called back and a male answered "IRS". I Said "I got a call from you guys and I assume it is about my overdue refund."
Surprise he hung up. How rude. Scammers have no manners these days.

Yes called saying they were from the IRS and they were trying to collect a debt just another way of bill collectors trying to catch you

Got a calls from them in three days role finally setup voice mail and robot message said IRS is filing lawsuit against us. Do i need to call back?

I'm sure if it was the IRS, they would not show up on my caller ID as "wireless caller".  Also, the IRS has stated repeatedly that they do NOT call people to collect money, nor do they call to threaten lawsuits.  They would contact you via registered mail.  The people using this scam are the lowest of the low.