On Nov 4th I visited the place with friends and family to have some drinks and snacks. We were a group of 14 people, and despite accommodating our table, they informed us that we had to scan a QR code to see the available menu and then go to the bar to place the order. The order needs to be prepaid in advance and then it is delivered to the table, when I paid, the waiter took the payment terminal away from my hands and pressed the button to pay in USD (US dollars). I always select payment in EUR (Euros) because my credit card does not charge extra fees for currency conversion and the conversion these machines apply is abusive. The waiter told me it was MANDATORY to pay in foreign currency and pointed to a sign next to the register. This practice is ILEGAL according to the Spanish law. The customer cannot be forced to pay in a currency other than the legal tender (EUROS). Paying in foreign currency can be done only if the customer chooses VOLUNTARILY to accept the exchange rate presented. I filled an official complaint form that I registered with "Comunidad de Madrid" requesting to be compensated for the difference as well as demanding that the ilegal sign be removed from the bar. I want to highlight that this is not the waiter's fault, that they are following orders from the owners. But still, if you face the same situation, refuse to pay in USD and if they still charge you, ask them for an official complaint form, get them to sign it and put the business stamp on it and have it registered with Comunidad de Madrid at this URL https://www.comunidad.madrid/servicios/consumo/presentar-reclamacion-consumo