I'm with Carol--I fly a lot, both domestically and internationally, and I think all the legacy airlines have minimal customer service as a general matter. They're a lot like flying Greyhound busses, only with less legroom. It's when things go wrong--cancelled flights, late flights, overbooking--that a legacy carrier can either rise to the occasion and surprise you or tell you to screw off and consign you to airport hell. Partly it's a function of the luck of the draw--get a sympathetic gate agent or decent customer service rep on the phone and you might make out okay. But if you get an ignorant or lazy or overworked or just plain mean agent, well, welcome to sleeping on the floor at the airport.
One thing that I've done is, when I get a particularly helpful customer service rep on the phone, I try to hang on to them. I ask for their identification so that I can send an email thanking them to their supervisor, and then I make sure that I send that email. I also ask for their direct extension so that I can call back if need by without having to re-explain the situation to a new agent. Then I add that information to my PDA--I now have a list of several potentially good customer service reps for the airlines I fly the most.