You guys should hire a lawyer, one that specializes in IP Law, Apple won't refund the buyers of the stolen copies because they're not the direct beneficiaries of the money the copiers earned. You'd have better results at receiving monetary damages from the IP infringement if you sued the developers who published the game on the apple store than continuing talks with Apple. Their legal team knows they don't have any obligation to do a full refund unless its proven at court that they're liable for it. A permanent ban is doable but on the long run, the perpetrators can just make new accounts. So that just looks like a cost ineffective request to Apple since if they set a precedent they'll have to use resources to ban developer accounts that uploads copies or copy cats of your game and then other devs can use this case to make those request as well.
Full support to you guys in practicing your rights but you've got to be efficient and smarter about this.