My experiences with Apple Tech support have been uniformly good to exceptional. I have heard of others having not so stellar experiences, which is to be expected. Everyone has a bad day or bad moment, and sometimes you just happen to run into that certain someone you immediately clash with.

I've seen the same thing with Dish Network, though the overall level of support quality isn't as high as I've had with Apple. As a result, what I tend to do when I have a bad support experience, is to vent to my wife and whoever is nearby, get my blood pressure and temper back in control, make notes to clarify what I now know about my situation, and then call back hoping to get someone else.
Rarely, do I get a repeat of bad service from anyone, including AT&T (a frequent whipping boy) when I do that.