I once took a tech support call from a customer who knew nothing at all about what he was doing. The customer purchased a high-end server from us along with a linux based operating system that has a web-based front-end. He called for help, but in the end literally wanted me to set it up for him and get around paying for it. After being very curtious on the phone he grew impatient because he wasn't getting what he wanted. I was trying to help him and teach him, he just wanted it done.
Eventually he threw a tantrum similiar to my 3 year old niece, started calling my names, insulting my intelligence and finally he reduced down to making fun of my mother.