jedediah:
I don't see anything wrong about going the extra length and fight back at a merchant like this, merchants like Mr. Free needs to learn a lesson about business ethics because obviously he didn't learn enough about honesty from his parents, now he's working in this society, making childish mistakes is not tolerated any longer, he's not a kid anymore. If you are the victim here, and you choose to think that he's just a "rude jerk" and do nothing and walk away, he would be laughing all the way to the bank, just because you didn't care.
This Mr. Free is a very typical person that had his life too easy, probably have never got into much trouble before for whatever he did because maybe when he's younger, people surrounding him all thinks he's too cute and its okay. In terms he started to think that he's special in this world, he doesn't have to worry about those consequences that we normal people worries about when we consider taking any action, now he's getting older, welcome to the real world Mr. Free. Its time to learn about being realistic and honest, and consequences for failure.