I guarantee Apple automatically refunds users when they ban a scam app.

Any iOS user can get a refund from the App Store, they just have to ask, and the process is pretty much automated.

Unfortunately few know this. I had a template email for unhappy customers that would walk them through it.

What if Apple has already paid the developer ? The money is in their bank account. Then Apple is at a loss.

I don’t know the details of all of Apple’s refund policies, specifically how far back they go in cases like this. But I can say Apple isn’t worried about taking a loss to ensure their customers get treated fairly.