i had something along the same line..i worked at a carwash. they would always give me crappy hours..not too little..too many. they would always say..oh we schedule you for so much because you need the money dont you? but it was alwats because i was the one who worked my *** off and did the job of like 3 other people plus my own. i had requested a day off for something important like 3 months in advance and they approved it, then the day before my boxx was like no you cant have it off you have to work..and i was fed up with everything. like you said there were numerous excuses..i worked there for a year and a half. so i waited for him to go to lunch that day (after taking $50 everyday OUT OF THE REGISTER for lunch like clockwork) waited, told my manager what i was doing (he was cool), he went home first so he couldnt be blamed..i sent all the employees home that i could (i was a supervisor), sent everyone home, waited for the work to pile up with no one to do it, waitied for my boss to come back and he came to me b*tching about what happened and to make me do all the work, told him what was up and left.
and my manager told me to put down his cell number on job apps and hed still be a reference for me //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif
we're at the age where we can find another job no problem.
BTW: that place has been open for 3 years..and has already gone through 500+ employees and the boss cant figure out why