I don’t think you seriously considered the impact of your A-G requirements.
The (f) category of visual and performing arts is crucial for admission and usually trips up a lot of OOS students.
http://www.ucop.edu/agguide/a-g-requirements/f-visual-performing-arts/index.html
If you didn’t get a decent grade in this “theater” elective, then they can withdraw their admission at anytime. If you omitted it in your calculation, “because it didn’t apply to your major” then they could consider that as being deceitful.
You can’t claim, "I didn’t know about this requirement " because every counselor and scrap of information mentions the entrance requirements from the A-G list. The UCs are adamant about including it everywhere and if you “didn’t know”, then they can ask, “Why wouldn’t someone, who wants to attend our elite universities, read that crucial, basic piece of information?”
It doesn’t matter what your major is because if you can’t get in, your major is a moot point. Then math kids would only take high school math classes, and English majors would only take English HS classes. They want kids exposed to all of the disciplines.
As for an appeal, you need to find out why they think you didn’t meet their criteria. Then address that when you find out. I would also sign up for the CCs before they run out of classes.