After you file

I spoke to an agent two days ago who said that she didn't see any notation that a letter went out, but then I got a 4464c dated 3/15/2018. This is crazy.  If they are going to send a letter, why not state what they need verified?  That is, if they even need anything verified.  This is crazy. I was filed/accepted w/ TT 2/9/2018. I've been in this WMR loop of "still being processed" since late Feb.  570 code w/ 3/19/2018 processing date on my transcripts.  I am not using TT next year.