My friend and I walked into mall, we bought a drink, and the cashier was supposed to give us back one dollar. Right after I gave her money, she put it in and was like stare straight ahead-I thought it was strange. But I was busy trying to find spare changes that I almost missed it until my friend reminded me. (since she was eager to get the drink -_-')

Then we waited until couple people went through and we asked her for it. She insisted that she gave us back (liar!) and pretended like nothing happened. She called someone else to reason with us. We showed her our pockets-which only had few cards and some coins ranging from 5 cents to 10 cents. Eventually, this OTHER girl gave us one dollar back. However, we felt so uncomfortable and so angry. I know people make mistakes, but not in this case. When people made mistake, they'll still remember it after a few minutes..

This beverage chain is pretty big, shall I report her even though this other girl still gave us back our change?
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Hey, thanks for all your answers, and I'm trying to figure out the best way to do it. Your answers are all very helpful.