You need a stable internet connection to purchase coins and packages.
If you cannot complete a purchase due to a connection error, try again in a place with a better internet connection.
If the problem still doesn't resolve itself, there may be a temporary issue with the store you downloaded the game from.
Try again after some time has passed, or try restarting your device.
All in-app purchases are conducted through the store you downloaded the game from.
As such, if the situation does not change even with a better internet connection, it may be due to one of the following causes:
・Your payment information is incorrect
・Your payment method is not accepted by the store
If you cannot resolve issues related to purchases, please contact us via "Menu" → "Contact" in the top right of the Home screen.