[CRConrad]

From all I've seen, heard, and read about that problem over the decades (yup, I think it's not mere years any more):

The only solution is to be rock-solid in refusing to do anything if there isn't a ticket for it. Your nine-thousand-percent-consistent reply to those emails, text messages, and voice calls needs to be "Yeah, make a ticket about it. I've shown you how, and that's the way we do it. No ticket, no action from me."

If you can't be that "mean" about it, you'll have to be a make-my-own-tickets doormat forever. In that perspective, doesn't feel all that "mean" any more, does it?