Be "that parent," epoh! Be friendly, firm, and treat them like professionals, but be vigilant. And then say thank you to the people who step up.

But yikes, it's not like anxiety is at a minimum at the start of the school year or anything, right? I hope you can get him going asap!

Document, document, document. I find it really effective to refer to "your email/ our conversation 12:50 pm on August 26" when sending another email, as it shows them that I'm not only paying attention, but I'm keeping a record.