Everybody has bad days and everybody has dingbat moments. And, of course, there are some people in the world who are nice and friendly but have little concept of time or other people's feelings. Perhaps that's the sort you were dealing with? The right response is to ask for what you want. That's true in dealing with just about anybody, BTW. It is perfectly reasonable and respectful to let people know what you want from them. If they refuse, then you have a problem. But if you don't speak up, then you are as much at fault as they are. I work retail too and sometimes we get swamped and during a multitask I will treat someone unfairly. And yes, a big sale takes precedence over a small one. The best customers are the ones who know what they want and can tell me. Those customers get what they want 99% of the time whether it be service, products, or attention.

Tell people what you want and give them a fighting chance to get it right.