I have had consistent issues at my job regarding scheduling. I told them I would be starting school soon and so my schedule would have to change; they said they'd be totally willing to accommodate.
However that has not been the case. They did not honor my new availability and I had to go to HR and get my schedule changed. This has happened a few times since, with me even being scheduled during finals. I've also tried reducing down to 20 hrs but they kept scheduling me for 30 hrs, so again I had to get that changed.
This latest time, I decided to just switch over to an on-call position. I have to come in once a month and from there I can just pick up shifts. The current schedule is still in effect, so on the days I'm unavailable I am simply calling in. I am taking my time back so I can focus on what truly matters to me.