I work casual in a restaurant and they put me onto the roster without asking for avalibility and denied when my co-worker told them they couldn’t work new year, what do I do

It's not the first time they did so. We also do get half cash in hand and other we get electronically but this only happened recently. I am thinking of quiting due to the poor work environment. The restaurants in a club but we don't technically work for the club and we don't even get weekend rates just a minimum wage for the whole week.