Are you pissed at the limit or the employee? The employee didn't set the limit, the store did. They probably did for a reason even though you can't see it. The employee probably had to tell 20 people already that they can't buy more than the limit for certain items. Half of those people probably #####ed and moaned so maybe cut the employee some slack for having to deal with that all day. Maybe she was snarky but put yourself in her shoes. It's tough on all of them. Try to remember that.
No sign up is a problem, I'll admit, but maybe it fell down or was moved or who knows. Or maybe the girl was wrong and there was no limit. If you felt that you could have found the manager and asked I suppose.
I know a couple young adults who work in grocery stores and they are stressed to the max. I just think we should all be aware that it's a tough gig and maybe cut them a little slack.
my