A couple things to the OP:
- Yes, I think the punishment for getting a C is extremely harsh, especially given the strong course load you had.
- I would definitely drive back down to Berkeley and not rest until I've spoken to EVERYONE that can help you (I would talk to anyone who would listen down there from the dean to the janitor). But I also, wouldn't put all my eggs in one basket. Try contacting other schools (LA and Davis) and speak to everyone you can. Make sure you really communicate to them your story. I think it is compelling enough to change some peoples minds. Good luck I hope things work out!