puchase delay

hi i just registered my debit card with i tunes hoping to buy an in app purchase from a game i am playing. it debited my account for $1, that is fine. but it didnt debit it for the amount of the actual transaction. when i checked my purchase history, the transaction is there for $30. i havent received the item in-game though. my question is, is there usually a delay with in-app purchases using itunes? if so, how long does it normally takes? i need the purchase to push through today because there is an event that ends later. if my purchase will be delayed, it would all then be useless for me. please help as to what i should do... thanks!