Unable to complete in-app purchase despite valid payment and balance

Hello,

When trying to make a purchase in Clash of Clans, I get the error:

“Your purchase could not be completed.”

My payment method is valid, and the issue persists across attempts.

Additionally, I have used an Apple Gift Card to fund my account, and I still have a sufficient balance available.

Please help resolve this issue as soon as possible.

Thank you in advance.

[Re-Titled by Moderator]

Original Title: Your purchase could not be completed.