The simple answer is that they think of you as an employee. And you aren't being paid. If you dont feel your cut is fair (and based on what you are saying it

The simple answer is that they think of you as an employee. And you aren't being paid. If you dont feel your cut is fair (and based on what you are saying it looks like thats the case), you should quit and feel no qualms about it. Treat it like an employment situation. If your job was bad, there's no reason to continue working there.