Workplace isn't WORKING with me...

I'm starting my last set of pre-reqs in a couple of weeks. I'll be in Anatomy & Physiology 9AM-10AM on Monday-Friday and Psychology, what they call half/half, meaning I attend 2 days from 10AM-11AM on campus and 3 days online. My work schedule is set at Sat-Tues 7-4. With that just being 32-hours, I asked for a decrease down to 24 hours, to leave time for studying and less stress through pre-reqs because I stress about my GPA (it's only a 2.85 right now, so it's cutting it too close and I want it a lot higher) and exams. Also, the people I work with are horrible and stress me out, also I'm working in 100+ degree weather right now...at walmart. Well after I filled out the request form, they denied it and said they could knock me down to 3 8-hour shifts and 2 4-hour shifts. That's not what I wanted at all. Hell, I don't even want to work there, let alone not have them work with my schooling as they all claim they do. I couldn't imagine how they would have reacted if I put down 20-hours maximum like I truly wanted to.

Basically, I feel aggravated and am just wondering what you guys would do in this situation or if you have been in my shoes before? Honestly, I don't HAVE to work. I can afford to live as a poor college student for a while until I could find a healthcare-related job. I'm just torn between choosing whats right and don't want to screw myself over.