yep, same thing happened to me
hopefully you have the emailed receipt/order # for it,
email apple and they will respond within 48 hours, with amazing customer service [not sarcastic, it was amazing service]
they will appologize for the inconvience, give you a credit, lecture you on backing up your transferred purchases, and send you a customer service review in a week
i would imagine they can only do this so many times
but remember
Always back up your wifi Purchases because if you dont, they will disappear