Apple gift card credit

I have recently redeemed two 50 dollar apple giftcards I redeemed them towards a game I really like. After checking how much game currency I had it was way below what 100 dollars was worth. (40$ missing) I checked my balance and it did charge me but it just says that the credit is “pending.” I just wanted to know how long this would take or if I have to refund it and to anyone that responds thank you.