the one true God is Doctor Doom and we should all be worshiping him.
When I had to deal with bad/rude customers, I work with them to find a solution to their problems and I'd say 95% of the time they came to reason and we found a way to fix what their problem was. If they continue to be a nuisance and refuse to accept any of the help that I offer then that's when you hit up your manager to deal with them because clearly there is something wrong with them.
Of course on the other side it makes me more irritable to other customer service people when they're being less than helpful, especially when I get all "If I did my job like you're doing yours then people would literally fall out of the sky."