When I worked retail I don't think I had any issues. The worst was maybe some idiot who stood in front of the bakery (I worked in a bakery inside a supermarket) waiting to be served. However he didn't stand in the entrance and made no indication that he wanted attention, so I ignored him. I assumed he was just browsing the bread on display.

Then I did tech support for Asus. One guy phoned up absolutely raging because his laptop had no operating system. In hindsight I'm pretty sure the hard drive was DOA but it didn't make a difference. No OS? Return it to the retailer. Asus laptops generally didn't ship without operating systems installed so something was inherently wrong with the computer.

The guy absolutely lost it with me because I had the audacity to tell him to return it to where he bought it from. He decided that it was personally my own fault that his laptop didn't have an OS. I was pretty amazed by this. I wonder how that guy went through his life. Sometimes you buy shit and it's defective or broken and then you return it for a replacement or refund. That's a normal fact of life. I don't know how grown adults cannot comprehend this.

The kicker was that he claimed to be a computer engineer, but then lambasted me for suggesting that he could download Linux when asking me where to find it. I mean... how else are you going to get a Linux distro? They're not that big even if you're on a slow connection... is there some other offline source for finding Linux distros I'm unaware of?

But yeah, he was the worst customer I had and I guess his complaint about me went directly to me. I refused to let him speak to a manager because he was a moron and it would've been a waste of my manager's time.