This was an in-app purchase then? Did you try contacting the app developer directly, either through their web site or whatever contact info they provide (Backflip has a web site I know that much)?
If you have and they refuse, then I would contact your credit card company and dispute the charge through them for a purchase without delivery of the product.
Of course, the one problem you may encounter is if this occured well over 7 months ago, the card company may refuse to act on the disputed charge after all this time.
I managed to get this responce:
If you are using an Apple device and have a billing issue:
Unfortunately, we are unable to give refunds directly since billing is all done through Apple. You can request a refund from the following link:
Got to chat with a nice apple support person and unfortunately the purchase was too old to get refunded.
Good strategy from Backflip Studios to delay answering untill its too late to refund
I hope this might help other people with purchase issues