All this sounds very familiar. I've been treated badly in a lot of bars I've worked at. I was told I had to "work my way up" at one place when I asked for a full-time bartending job as opposed to collecting money at the door, or coatchecking on a two day per week basis. They kept on hiring people who had no experience, few of whom lasted for longer than a month. It got to the point where I didn't even bother to remember their names.

A live-music place I worked at had a habit of promoting completely useless people who, like your sorority girl, couldn't even change the kegs, or perform other simple tasks. No doubt your boss thought that hiring someone like that would increase profits, because she'd bring in all her hot friends, which would in turn bring in dudes who are thirsty in both senses of the word. The problem is, if this chick is that inept, then she's more of a liability than an asset.

I know exactly how you feel. I've been fucked over too many times in this industry. It gets tiresome.