Burger King In Prato

The restaurant does not accept coupons but the sign is not clearly visible as it is next to the independent cash registers but at the same time it is not immediately visible because these are placed obliquely, so I inserted the coupon and paid for both the coupon and the sandwich in the bill. without discount, in short, sandwich without menu + coupon that didn't give me anything €16. I reported this to the cashier after payment but unfortunately without the manager they couldn't do anything. I therefore gave away €5 without being able to get it back as I didn't have the opportunity to come back the next day.