Today, I rang up a customer and set up my part for the credit card to go through. I told the customer that I needed her card slid and she mentioned with an attitude that she had already slid it and made her selection. I informed her that it must've cancelled out somehow and she ended up sliding her card. She told me that she didn't want to get charged twice. I mentioned that she would only get charged once the transaction goes through. After she signed the slip, she left quickly with her groceries.
I double checked with one of the service desk employees who mentioned the same thing I did to the customer. A few minutes later, I got a customer who understood that the credit card doesn't get charged until the transaction goes through.