I mean, it's one thing to be given the runaround and then have to get very firm with someone, but it's another to get abusive, use foul language, yell, etc. At that point (1) the customer service person shuts down (who doesn't?) and (2) their obligation to do business with you/work to solve your problem is over, as it should be. No one should have to go to work and put up with verbal abuse and threats by customers.

Plus, that whole "you catch more flies with honey than with vinegar" is so true. Sometimes, I've just said to the customer service person, "I have a problem and I'm hoping you can help me." No blaming, no accusing, just saying that I need them, plain and simple. I have to say that my negative interactions while shopping, dealing with utilities, etc., have been so few, I can remember them. (Grrrrr Qwest, may you burn in hell forever!) ;)