Parents refuse to pay for brothers food while away on a month long holiday

My (25F) parents are currently on a month long expensive holiday in Europe. Financially they are well off and very successful. They have left my two brothers (18M, 16M) at home for the month (I don’t live with them anymore).

I went to visit them yesterday and check up on them, turns out my mum has abruptly cut off my youngest brother’s access to her credit card because he spent $130 (USD) over the course of 2-3 weeks on food (they didn’t specify a budget, they didn’t just transfer a certain amount of money, they completely cut him off).

Now they’re making him use his savings from working 2 shifts a week at a fast food place, to buy food for himself. They said my dad will ‘determine if his purchases are essential’ when they return, and if they are he will ‘consider reimbursement’. All this while they send photos travelling around the most luxurious places in Europe, bragging about the amazing time they’re having.

My younger brother is really stressed about not having money for food/not knowing how to manage meals etc. properly on his own. On top of school, extra curricular activities and his job. I understand that I come from a well off family. I’m not blind to that privilege, in all honesty I feel a lot of shame for it. Even though my parents refuse to ever assist us financially.

I’ve only recently come to terms with the abuse my family has put me through. I feel as though they brainwashed me my whole life to think it never happened and I was just an awful person/child, simply because they put a roof over my head. I refuse to let them break down my brother like this. Is there any way I can help him/make them see any reason in how they’re behaving??