If you won, but now you don't have any withdrawable credits, it is because you have already used the credits toward other orders.
When you place either a manual order or a Smart Order on Jackpocket, we will always use your non-withdrawable credits first, such as credit from fund requests, referrals, promotional, etc. If you no longer have non-withdrawable credits in your Jackpocket account when you place the order, we will automatically use your withdrawable (winning) credits.
On the checkout screen, it says how much is used in credits and how much is charged to your card on each transaction, as well as in the email confirmation you receive after your order is placed. You can also view your transaction history from the side menu of the app, it shows which orders your credits were applied to.