I originally accepted an offer asking to work part-time for specific days and hours but my job just changed them to whatever hours they wanted a couple weeks in. One week they didn’t schedule me at all and ignored me even when I asked them about it. Other times they schedule people for full shifts but force people to go home mid-shift if they’re full staffed. I feel like it’s unfair for them to change up the hours they gave me as they see fit yet expect me to notify them in advance about my availability. I didn’t get it written on a contract or anything, for future reference is this something most employers do or do I have to go out of my way to make sure I keep the terms that I signed up for?