Hey, I totally agree with you there. I had a similar situation back in 2007 where I was expected to do 3-11 every weekend. For some reason my workplace can't resist to put me on 3-11 shifts. It sucks the big one when people do that. Doing the equivelant of a full days work starting 3 in the afternoon is lame.
Also, they have this tendancy, now that I'm nearing 21, to say they can't afford me because I cost too much, but ring me up, several times a day asking if I could come in and refusd to take no for an answer, despite being a PPT. You don't work at Woolworths by any chance?