I mean, your SM gave you more hours than you requested (most people would be thrilled), you understandably requested to have less hours so you can focus on your studies. She obliged and cut you down to four and none. You complained and she gave you your original requested hours during the time of the week that would least inconvenience your studies, and you’re complaining.

It very much seems like you don’t want to work, and that’s fine, you’re in high school, you should be able to enjoy your youth before living on your own. But I will say this: remember that other people at your store rely on their hours—hours that your SM is giving to you and therefore not them—for their rent, food, etc…if you actually wanted/needed to work, you wouldn’t be complaining about getting too many hours/working your requested hours when you’re least inconvenienced.

if you change your availability on the app then your sm cannot schedule you through the scheduling system. if they’re still able to do so something is wrong and you need to check in with her again.