Oi, I remember getting that all the time. Use the eggs to build a solid base for the bag, then put a couple loaves of bread (like Wonder bread or similar) on top to fill up the bag without putting anything heavy on the eggs.
NOOOOOOOO! You'll BREAK THE EGGSS!!!!!!!ELEVENTY!!!
Ummm, no. Not the way it works. I mean, our cooler had dozens of eggs stacked 15 deep. You think your three loaves of bread weigh more than a gross of eggs?
Of course, that would mean applying (un)common sense to the situation.
I feel for you, and I doubt I could ever go back to being a register jockey. I would either get fired for brow beating people with sense or physically beating them with a belt divider. Or possibly both at the same time.