I published the app under the GPL-3 license, and with a clear statement that says "It's not allowed to publish, distribute the app, or use it in a commercial way".
They neither respected the license nor the other conditions.
If you release something under self-contradictory licensing terms, and then people use it in a way you didn't expect – maybe the problem was with your self-contradictory licensing?
And it's not clear that the copy is used in a commercial way. If the app is free, maybe they follow your full conditions?