Quoted:
I can't stand it when someone calls me on a cellphone, and I'm in the middle of something, so I tell them that I'll call them back in 5 or 10 minutes and then when I call them back they don't answer. I just don't fucking get it. If you wanted to talk to me 5 minutes ago then why the fuck do you not want to talk to me now ? This highly infuriates me.
Maybe THEY can't talk to YOU now because THEY are busy. They called you when they had the time. Not everybody revolves their entire life around your schedule. Just maybe you're not the only person they need to talk to today, and when you called back, they were taking care of some other business.
You aren't the only person in the world, you know.
edited: As a business owner, I've dumped more than one customer for being an arrogant prick. And it's usually the small-time customers that are this way. The bigger customers usually understand things happen.