Yeah... I hate it when the play games with your schedule. Thats the reason I eventually left Hardee's after over a year of service (that, and having never got my evaluation for my raise. It was six months late by the time I finally quit). It all came to a head when they didn't want to let me off for some of my exams! I would have worked full time for them once that week was over, but they just had to push.
A schedule they make up doesn't have to be followed. You don't have any rights on the job (except the right to organize a Union). You'll notice somewhere in your employee handbook it says, "This is Not a Contract". All employees in the States without a union contract serve at the will of the employer. They can fire you for any reason (as long as its not discrimination based on sex, religion, race, handicap or old age). Their are only two ways around this... you can either "Act Union " and give everybody in the store united to take direct action if they mess with any of the staff, like say... if they don't give you a fair shake on the schedule, everbody threatens to walk out that shift. Or you can organize a union that will be recognized by the government, get a collective bargaining agreement (a contract) and include it a list of discplinary offenses and a process that it can be addressed.
You probably don't have time to deal with any of this right now. When I was a student working fast food, I had the same problem. I didn't have time for my studies... much less time to fix the crappy way Hardee's was being run. However, if your still doing fast food come summer break you might consider trying to organize some collective defense.