Oh boy. He was out of line for sure with that second call. This is just my opinion.... Is it your job to screen his calls? I don't think you did anything wrong, but I don't think I would have just said "No, thank you. Have a nice day" and hung up. That seems kind of abrupt. Since what he was selling wasn't entirely clear I would have just taken a message and let the boss deal with it.
What's done is done though and I would tell the boss the situation from your point of view so if the nut calls back and gets him he will have a clear idea what's going on.