I should have included the fact that we didnt have contracts.
Rasmus Filipsen

Contracts do not have to be written down, they can be verbal. If you all agreed to the prize money being split 20% each, and no money going to the organisation, then you might have a case.

I am still only a student of Law so I can’t offer you any legal advice though I would suggest bringing it up to a lawyer who will better know if you have a case.