WHEN THIS HAPPENS, boo loudly.
Then buttonhole them unpleasantly later and complain about
“insensitivity.” Don’t worry what they think about you, or whether you
actually convince them of anything, just make sure the interaction is
personally unpleasant enough that they’ll want to avoid such in the
future. That’s how this sort of thing is done . . . .
This is a Confrontational Management technique I learned in the military bureaucracy; increase the Other Guy’s level of pain until he bends to your will. Oh yeah, that’s what the military does OUTSIDE the bureaucracy, too.