If you are having difficulties purchasing Cluster coins due to an error, please check the following:
Check your credit card’s security code
For some companies, you will be able to register a credit card to a website even when the security code is incorrect. Please ensure that you have entered the correct three-digit security code and retry.
Check your credit card’s upper limit
Cluster coin purchases may not go through if you have passed your credit card’s cashing/credit upper limit. To check your usage history and the upper limit, please contact your own credit card company.