That really sucks, and yeah, it happens more than people think. I’ve dealt with the same — it’s demotivating. One thing that helped me was switching to platforms like
https://www.gambody.com/ where there’s a bit more oversight and copyright control. You can actually track your downloads and keep it all a bit tighter. Plus, when models come from a trusted source, buyers are less likely to end up on shady resale sites.