If you receive an email detailing that "Your Aion Classic Siel's Aura subscription has been canceled" after attempting a purchase for a Siel's Aura Membership, this is typically due to a bank decline. We suggest you try your purchase again using a different payment method if possible. If you have only the one payment method which resulted in a bank decline, we recommend that you contact your financial institution to review why the attempt was declined.
The best way to confirm if your membership purchase was successful is to log into your NC Account and click the Transaction History tab. Then click on Subscriptions and Aion Classic. If you see your current membership list, you are subscribed and your purchase was captured. If you are not subscribed, the option to Add Subscription will be listed, meaning your purchase was captured.