I worked in a retail store full-time while completing prerequisite courses in order to get admitted to university. My courses where all in the evening, so I struck a deal with my department manager. He didn't schedule me ever on evening shifts, and in exchange, I would take any shitty shift and tasks. It worked perfectly for a year. I was happy, my manager was happy and my coworkers were happy too. We stick with each other and made sacrifices for each others too (working together to get out of this hell hole of a job).
I only had 6 months to go before completing my prerequisite. Somehow the store assistant manager noticed I never worked evening shifts despite the store policy saying that every full-time employee must work one evening shift per week. I struck a new deal with my department manager to always work the same evening, it was easier for me to schedule things around (and just take one course less instead of missing multiple classes for multiples courses).
This enraged the assistant store manager who hated me with a burning passion (why ? a whole story in itself lol). Other shit went down in my department and they removed our manager, so the assistant store manager, who was now acting store manager because the real store manager was on lease to another store, took the managing of our department under his own personal responsibility. He refused to honour the deal I had made.
His first week there, he scheduled me only on evening shifts meaning I would miss two exams. My other coworkers came to my rescue and they all asked to trade their day shifts with me, pretending various excuses.
I tried to talk to the store owner but he was in vacation. I tried to explain my situation to the assistant manager but his answer was that I was asking for "students privileges" meaning I would loose my full-time status and would from now on be scheduled on students hours (28h/week, only on evenings and weekends). Obviously it wouldn't work.
I started arguing and he told me I had a choice It was either school or my "career" at [big box retail store] but I couldn't have both. I told him I didn't give a fuck about a "career" here. Then he told me "in a completely friendly and informal manner that my name was making the round for the next manager promotion".
I laughed at his face. I went back to my department. My two fav coworkers were there. I told them how everything went down, and how tonight was my last shift. I stayed the whole shift for them. We did nothing and sat in our secret hideout in the backstore.
This was a Friday evening. I was scheduled to work on Saturday and Sunday. Only me and our ultra sketchy and flaky temp guy.
I said fuck that. On the evening I went to the store manager, gave him my shirt and my badge, and told him I quit. He said I couldn't quit since I had shifts scheduled in the weekend. I told him to fuck off. Words quickly got out that I left and coworkers texted me saying they won't answer their phone when called to cover my shift. And they did. The store was stuck with a bunch of untrained temp.
I found a job the next Monday.