a) because I was raised like that

b) because you either hit helpful people that will likely help or pricks who will not. Difference is, helpful people might just flip you off if you come across like a raving lunatic, while pricks still will not care either way.

So, basically, by going to any store, shop, maker, whatever, and acting like a 15 year old you only lower your chance. And while I don't mean to berate youth (some are certainly good people), attention span and patience are usually associated with maturity.

I also work in IT and while I don't have millions of customers, I sometimes answer to as many as 30.000. And I want to help, I really want, but bugs are inherent, sometimes it's not even a bug, a power failure corrupted some database record somewhere. Maybe an idiot pressed Cancel.

I want to help and fix, I really do, and apologize and be quick and prompt, inspire professionalism and trust. But no matter who you are, if you stop five meters away and raise your voice so everyone can hear how you've been wronged and berate me and my job we just might have run out of bytes to fix your issue. That's on a good day. On a bad day, I might just be honest with you.

Always be calm and polite. If nothing else, at least let them come across like raving lunatics.