After the first time charging with a credit card

Nexon's site refuses all other credit cards I've got.

Any idea what's the problem?

UltimatePay's site has this to say in their FAQ:

Question
Why Was My Credit Card Declined For My Purchase?


Answer

There are several reasons why Credit Card payments may be rejected. Many may need to be handled directly with your credit card company. It is also possible that your order does not pass our fraud protection measures.

We do take the safety and security of your account seriously and use very strict measures to prevent abuse or theft of credit card information. If you feel your order is being declined incorrectly, please try the following steps:

- Make sure that your account billing information and address are correct and up to date.

- If you are paying for someone else, use your contact information, not theirs, when completing fields on the order pages.

- If you are new to our service, you may have restrictions on how many orders we can accept in a given time period. Try waiting 5 business days and placing a new payment. This restriction will lesson after you've been an active customer.

If your payment is still rejected, you will need to select a different payment method for this purchase.

We apologize for any inconvenience.

UltimatePay's site has this to say in their FAQ:

Thanks, guess I'm a new costumer so I can only buy every 5 days... Not too bad.

This restriction will lesson after you've been an active customer.

Lols

Nexon's site refuses all other credit cards I've got.

Any idea what's the problem?

Might be like with PayPal? If you use one PP account and then try to use another, it will tell you that your Nexon account is temporarly locked to the first PayPal account you used. I think the lock is 1 month but I'm not sure.

It's been many days since my first (and last) time trying to charge through nexon's site with a credit card.

It still gives the same error message both on the card I first used and the other ones I have.

Maybe try contacting UltimatePay and asking what's wrong?

I got that message but after I waited those 5 business days it accepted my card again.