I'm always kind of amused at these administrators that think "withholding" a high school diploma is some kind of horrible punishment. As long as you meet the state requirements they can't stop you from graduating. When you get that piece of paper, most people stick it in their keepsake box and never look at again anyway. For college and job purposes, they only care about your transcript from the Board of Education, they couldn't care less about the diploma, in fact I have never been asked for it in the 25+ years since I graduated high school.
Heck, and with the quality of laser printers, just get some high quality paper, a copy of Printshop, and make your own if it means so much.