Poor management - Part Time Sales Associate Superga Employee Review

Told to commit at least 20 hours of work to get paid $12/h, plotted 20 hours but given lesser hour and getting paid $10/h. Gave 2/3 working days each week as I have school but was told that I will not be given any shift for the ENTIRE MONTH as it’s VERY LESS HOURS. THIS IS NOT STATED IN THE CONTRACT EITHER. They also won’t care if you have examination or not. They will tell you they need people to work cause sales period and say cannot cancel shift.