My question involves employment and labor law for the state of: California.

I work for a rather well known company called sears. in my department, consumer electronics we work for 6$ base pay + commission, in my department i am the longest one there going on over 2+ years, today they decided that 3 employees will get 30+ hrs a week all being part time employees and working 12 hour days, pretty much open to close on the weekends while the rest of the employees in this department including myself get 10 hours a week and only work during the week not on weekends. we work on commission, most of our money made is during Saturday and Sunday so not only are we loosing our hours but our chance to make a lot of our money. is there anything we can do? i feel like there is got to be something that should be able to stop them from doing this, im not asking just for myself but for the other people in my department they all older and have bills to pay plus school and i feel bad for them. Thanks in advance for any help/advice given.