I Pre ordered dungeons 2 but as soon as it released it says my payment Declinded

If the pre-order payment was declined at release, the supported path is to check whether the pre-order is still present in Order history and update the payment method there.

1. Sign in to Order history at https://account.microsoft.com/orders with the Microsoft account used for the pre-order.
2. Find the pre-order.
3. Select Change how you pay.
4. Choose a different payment option or add a new one.

Microsoft states that if payment collection fails, it will try the current payment option two more times before the pre-order launches. If payment still cannot be collected, the pre-order is cancelled.

For the item itself:

• If the game page now shows Install instead of Buy, select Install.
• If the order appears to have gone through but the game still does not appear in My games & apps, contact Microsoft Store support.

For the pre-order cape specifically, the available guidance indicates that if there is no trace of the order in https://account.microsoft.com/orders and the game has already been released, the pre-order reward can no longer be obtained.

References:

• Pre-orders for Microsoft Store
• Minecraft dungeons 2 pre-order issue - Microsoft Q&A