Okay, I'm not excusing his lack of attention to you, but I also think what you said to him came off sounding a little confrontational, so he probably wasn't that interested in helping you after that.
That being said, I understand how people expect good service, especially when paying a lot of money for something, but you have to understand a few things.
1. People who work at these jobs get paid very little and have to deal with whiny customers all day long. More often than not, they are people who can't get a better job because they don't have good personalities or what not. Is this an excuse for bad service? No, but if you're getting paid $7 an hour, it's hard to get too worked up about helping people.
2. If people are giving you bad service, go somewhere else. Period. Complaining to the manager usually won't accomplish anything more than making you look like a whiner and embarrassing the employee, and it still won't make you happy. Just go spend your money elsewhere. Repeat, go somewhere else. Places with bad service won't magically provide better service just because you're complaining. It's usually the opposite.
If you have the chance to go to an Apple store, go there. Every time. Their service is always top notch and they do everything they can to take care of their customers.