This really sounds stressful! Been through this a lot and I have invested money but ended up other stores are benefitting from it. I came across this UNIQUE app, and it is very cool. It detects other stores that use my brand’s images and contents… It automatically sends a notification to me through email and it automatically deletes those photos.
Try it. they have a free trial.
https://apps.shopify.com/unique-anti-theft#reviews
Hope this helps.