This is why as a diagnosed claustrophobe I have four flashlights and enough batteries to keep it all running for 12+ hours on me. *shudders* Without lights, an elevator isn't much bigger than a coffin. Or a peanut butter jar.

I'd have used the emergency phone. And after about six hours, I'd be playing with their camera to get someone's attention- say a red micro strobe taped to the lens.