Shekwan
Kim Chi Quaffing Celt
Complain to whoever runs the place its in. If its in public, then I'd be angry and do nothing.
Slap in another bill and get the food.
I rarely use vending machines, and I only do when a) it's the only source of food around, and b) I'm starving; thus, putting in an extra dollar is justified to me.
I usually use C-4 to extract justice, but if I haven't got any handy, a crowbar gets the job done.