So, I was participating in a session of the European Youth Parliament at my school and we had a party the day before. Every comitee had to set up a table with food and I got my mom to buy it since no one else could (we only had the day of the party to get the food and we would be at school all day). Three of my colleagues brought their food so they didn't eat anything from our or any other table. It's been a week and only 2 people have paid so far so I decide to remind the group of their debt. Now they refuse to pay for it, since they didn't eat anything, despite the table being our responsibility.