Basically, for the last several months(including over the holiday season where, being retail, hours were abundant), I've been getting trash hours from my boss. Despite having full availability though the whole time, I've typically been getting around 8-15 hours a week. The reason being that my boss found me unreliable because I turned down a bunch of shifts offered to me while I WAS still in school because, surprise surprise, I was busy due to being in school full time.
As it is now, my boss has openly admitted to me that she doesn't want to give me hours, and refuses to call me for shifts except as a last resort.
I tried every form of working with her possible, and finally got sick of it and talked to the union rep when he was in my store today. He instructed me to put in a formal request for more hours, which my boss scoffed at and just said "I don't have hours to give you".
However, in addition to that, with that request made, I now have the ability to take the schedule of any employee I have seniority over(which is quite a few of the cashiers there) if they are given more hours than I am. Which basically means I'm set for hours - kinda sad I had to resort to this when I'm not even asking anything unreasonable - 20 hours a week would suit me just fine.
-- Joyrock Fresh from my first justified ban. Ever!
The first job i had bagging groceries way back in the day was at a chain of stores that had a union.
If it is at the point where you had a to go to the union just to get hours then it is probably time to move on to a different job. Right now maybe its just your boss that hates you, but when you starting taking hours from the other cashiers they are going to hate you for it too. Maybe another job just isnt an option right now but I think you should definitely be looking. Having to go through the union to get hours every time other week just isnt a good way to work.