When a purchase made on an Apple device fails, the only way to get a refund is through Apple, as they have the relevant information.
Support is correct when they give this response:
Thanks for contacting us and playing Clash of Clans!
I'm sorry to hear that you didn't receive those gems right away. Sometimes when you purchase gems, it may take a while for them to become available. In the meantime there is no need to purchase them again, because your previous order is still being processed.
If you still have not received a purchase made more than 24 hours ago, please contact Apple support for further information at http://www.apple.com/support/itunes/contact/.
I am very sorry for this inconvenience. We are working to reduce the delay in the future.
There have been instances when Apple has then told the player to contact supercell. This is incorrect advice. If this happens to you, please reply to Apple and tell them this, and you should receive your refund.
