I would go back and explain to the owner what happened. If he is a responsible owner, he''ll want your business and want to make things right. I think it was an error on the clerks part and for some reason there are those people out there that will not admit mistakes and try to turn it on you for pointing out their mistake. I've worked in retail for years and I've made mistakes, and I always thank people who point them out. I apologize for making them and if I am in the position to do so, I make up for the mistake with a discount. I have had people come in irate and leave apologizing to me for their behavior. The opinion they have when they leave will determine if they come back, not that I made a mistake.