Mom: *leaves the room and comes back with Diva’s agenda*
Me: *begins flipping through the agenda, showing her every single page that I wrote on or stapled*
Me: “Now, if you’ll notice, I have written in Diva’s agenda and stapled progress reports, letters to you, and lists of missing work into her agenda every single week since we last spoke, as per our agreement. Are you telling me that you didn’t check her agenda once?”
However, any principal I've worked with also knows this about the parents, so they put on a show to calm the animals down but trust you to do something to try shutting them up next time.