I'm not sure which service center they were dealing with, but other folks have mentioned the issue in the last few weeks.

Photograph the envelope and then I would put that envelope, unopened, into another envelope and send it to your local service center with a letter that says "HUH?" I actually had a rubber stamp made that said HUH? for the regular IRS letters that were posted the same day - one said you owe XXX and the other said your refund has been increased to YYY. I am bouyed by the fact that things have not really changed, even though they are different.  

I know this problem was also posted by at least one other user.