Zak,
You seem like a person with a conscience based on your previous posts. Take the high road and you will always know that you did the right thing. It doesn't matter how Cabelas treats their employees to you. The only thing that should matter is how you act in this situation. You can only control what you do and hopefully it will be an inspiration for others. As far as the change for a 5 and you get back change for a 20. Only 1 thing to do is point out to the clerk what they did and make it right. What goes around comes around.