Unfair treatment of employees - Anonymous employee Express Employee Review

Schedule is done 3 weeks in advance and off days have to be submitted before the schedule is done, yet my manager canceled my shift the day before or the day of said shift a few times. Sometimes employees are put "on call" and are required to call in 2 hours before their shift to see if help is needed, however no compensation is given for this time set aside. All scheduled shifts that cannot be completed require a replacement, even when extraneous circumstances crop up (such as swine flu contraction or snow obstacles)