It might be worth trying another Apple Store. Most Members have found that the Apple Store replaced their iPad for free when it was damaged - even if the problem was not due to Apple. It's an unofficial, 'once in a lifetime', "we'll deny it if you ask us" policy that most store staff don't even know about, so you might need to approach a manager.
Be polite, be humble, be honest and let us know how you get on.
Tim