I know what you mean! And I don't think you deserved those complaints, it doesn't sound like you did anything wrong. People always think that cahsiers have to be super nice all the time. But sometimes you get one too many snobby customers, and it just ruins your day. It's really hard to be nice after that!
Heh. I work at Subway... you can imagine some of the people I have to deal with...granted most people are nice... sometimes, you just have to grit your teeth and deal with it. So, yeah, I feel your pain..some people are just dumb.
Ugh, I know how you feel. Being a cashier sucks, but you have to always be nice to customers. Believe me I know it's hard, but it's better not to get on the customers bad side. :/
I don't think you're over-reacting. People are dumb and get worked up over small stuff like that. Some lady threatened to sue me because I charged tax on her dish soap...people these days. :/
But granted, I'd probably end up either getting snappy before biting my tongue as well.