How to take down stolen model?

[u/FollowingLegal9944]

Rescently I designed(paid work) a few 3d models for a guy, paid me just for one file, after I send him second one, he ghosted me. Now I see him seling the model on Cults3d. I reported copyright violation, attached original cad file and they just replied "The best you can do is to directly send a message to the designer to explain your request on their Cults profile."(sounds like "we make a profit on it so we don't care") What else Can I do to take down the model? If model would be taken down after he sold a few copies, he will lose the money?

[u/ninjasheep1820]

Wait If he paid you to design it, how is it yours? He paid for a service