I was recently at Pisa Galileo airport, I noticed the lounge there accepted both priority pass and diners club cardholders. Being I have a discover card (which shows a diners club logo), I ignorantly went into the lounge and inquired if they could swipe my card in their machine that logs in the priority pass holders and diners club members. They said no problem but warned me that I may get charged even though the machine is not a credit card processing machine but a separate machine altogether, and they don't know the fees for my foreign card that happens to show a diners club logo. I consented. After she swiped it, it showed up as a valid entry pass but reminded me if she clicks OK I MIGHT be charged an unknown amount. That's when I stopped the transaction and quickly called discover to inquire about this matter. They said they don't have any details and cannot help me. At that point I was getting close to my departure, and just gave up.
Does anyone know if I completed the transaction what charges would show on my card and if Diners Club associated with Discover would have helped in this case? TIA