Since Leaf may not be able to answer right now, maybe I can help:
- I'm pretty sure he hasn't signed anything. You two carried on a discussion on a community forum.
- That's not what you agreed to. You asked for permission to create your own game jams with any rules you want, or no rules at all. Which was fine all along: jam organizers on Itch make their own rules for participation. We just ask them to also mind the community guidelines and terms of service.
- Leaf here is the owner of the website. You've been talking to him all along.
Please do no resort to threats. That makes people less inclined to be amiable, and can serve as evidence in a court of law. What seems to be the problem, anyway? Is the restriction still in place? Maybe something went wrong.