“Payment by card only for purchases over 5 euros”

Purchase limit. A parent buys a cheese pie for his child, the store hits the machine and takes out the receipt. The parent shows his card because there was a POS next to the machine. Then the cashier tells him to look at the column, where clearly there was a handwritten piece of paper, which said: “card payment only with purchases over 5 euros”. The parent politely said that he had not seen it and that the store has no right to do so. Then the owner gets up and tells him, what to do, we don’t like it. The bank takes it from us. Do you want the cheesecake, will you pay cash or should I cancel it? The child had already taken the first bite. In order not to create tension, the parent buys another cheese pie and a coffee, exceeds the limit for card purchases, pays and leaves.