If you have an actual example of this happening, send a support email to Apple. They generally take this kind of thing fairly seriously (caveat: provided that t

If you have an actual example of this happening, send a support email to Apple. They generally take this kind of thing fairly seriously (caveat: provided that the app has a large enough audience). It won't help you immediately, but they may better scrutinize later updates from this developer. And they certainly will take categorical action if they find enough bad actors doing something to screw up the App Store as an environment.