How old is he? I would definitely go up to the school and talk to someone about it. I am not saying your son is lying, but usually a kid can't "Clear it up" with the office... It takes an adult. Maybe he misunderstood them, and he's actually still in trouble. I would definitely go just to clear things up in your mind.
Even if he did steal something, so what?? Unless this is an ongoing thing, tell them to fuck off... repremand him yes, but don't BAN him from the snack bar... UGH! I hate schools these days. I can only imagine what my son will go through as he gets older...
Just my
