A product of mine got sanctioned and appeal declined with no explanation, what can i do?

A listing of mine, of one of my best selling items in sketchfab got sanctioned here, based on a report. I appealed, and a couple weeks later it got declined, after ‘thorough investigation’, with the only reason given that it violated the rules. No specific violation got mentioned, and i cannot appeal again.

It says in the message, if im an EU Citizen, i can start a legal dispute, but to where and whom? And im not willing to spend all profits i ever made on sketchfab on legal fees just to get a falsely accused sanction removed.

I dont even know who reported my product. If this was a DMCA claim, shouldnt the claimant legally be required provide their legal/contact information to be reached for a dispute, for the claim to be valid? Its like that on other platforms.

The product is fully of my own design, i can proof that im the only one with the source development files.

Any others had this same issue? How did you get it resolved if so?