Do not lose the original CP2000 notice. If you have not received the notice closing the case at least 10 days before the current deadline to respond, then call the IRS back and your first question to the person you speak to needs to be "To whom am I speaking please, and where are you physically located on this planet?" THen if they say the 2nd notice has been sent, document your phone call and respond to that CP2000 notice in accordance with the instructions in that notice. Make sure you send your response certified mail, return receipt required (not requested, but *required*)