"Treating them however you wish" is highly subjective. Product support is a contractual agreement: if an organization provides inept, impotent support, then it shouldn't be surprised if it or its employees incur hostility via said support channels.

It's sowing the wind and reaping the whirlwind.

I've done time in the trenches, and frankly, it's appalling. People are hired by quantity, not quality, and were it not for scripts, 90% of the people in the call center wouldn't know assholes from elbows. The problem is that they don't continue their own job training upon hiring; if you crutch on the drone script, don't be surprised if you get called on the carpet or treated like shit.

I tend to be respectful of support techs, but if you've already got my money, I expect a certain quality of service as was agreed upon when I entered into the agreement. If the organization can't provide that, and instead provides bargain-basement CS reps, then I'm going to be rightly irate. Is it fair to directly express my irritation with said rep? Well, his/her wages are on my dollar, so yes, I think so, especially if it's obvious he/she has done nothing but the bare minimum of job training.

GNU/Turd?