Just a little story I thought you all might enjoy. The owner wasn't a terrible person or anything, I don't hate him, I just did what I had to do.
While I was going to college I had a part time job at a gas station sometime around 2007 or so. I got about 30 hours per week.
The job wasn't difficult, I brought in my school work and got some studying done during work time which the owner/manager was fine with so long as I got my duties done. There were usually two of us there in the evenings until about 10:00 and then one person on for two hours by themself to close. There were probably about two other capable employees there and about four that were fine, but not capable/willing to perform their duties properly.
I found that as time went on, I became the de facto closer of the place. I was fine with closing two or three nights per week, but didn't want to do it every shift. I went and spoke with the owner/manager one day and let him know about that. He seemed receptive and told me he'd schedule me to close less often. Cool.
The next week the schedule came out, I had four or five closing shifts. I went and spoke with him again a day or two later and re-hashed the same conversation. He once again said he'd cut down my closing shifts.
The schedule came out for the following week and was almost identical to previous weeks. I spoke with him as soon as I could again and was more firm. I explained that school was my priority and that closing that often was interfering with my sleep. I was fairly firm while still being polite.
The next schedule came out with no change in my closing shifts. I went in the next day and gave my two weeks notice. He immediately said, “I'll take you off closing shifts!” I declined to rescind my notice.