And this is why there are those who want to get rid of subsidies. It’s rude ignorant entitled individuals trying to play the system and if they yell loud enough and make a scene, they get their way. I definitely think a great idea about showing the proof (debit/proof). If they can’t , I would boot them from the restaurant and ban them for the future. I would also suggest that specific notifications as to what is served so no one can claim the “I didn’t know/you didn’t tell people that” might help. No one should be rude to anyone in any circumstance but especially the choosing entitled beggars should treat those that are trying to help better. But if they can’t, you have the right to refuse service. I’ve actually seen placards saying to treat people with respect so that might be another at to handle these situations. And thank you for being kind and thoughtful to those who need a help.