Currently, in-game purchases are available through the Play Store (Google) and the App Store.

Therefore, there may be a variety of causes as well as payment methods.

Please try the following steps to resolve the issue.

 [ 'Gran Saga Idle: KNIGHTS X KNIGHTS' Payment Issue Solution ]

 1) Exit and relaunch the game in a smooth network environment

 2) Issue with store account settings (contact the store)

 - Go to the Google Pay Support Center

 - Go to Apple's customer support website

 3) Carrier payment issue (contact your carrier)

If you have issues with your payment method, such as small payments or payment limits, contact your card company or carrier's customer support.