I have this same problem. I am trying to buy gems, I can only play for 2 more days of the Halloween event before I go on vacation and I really want to buy the Mad King Thorn outfit. I have tried multiple times ankittenep getting the “Card Approval Failed – Please check your card details and try again.” Now I have purchased $50 worth of gems before and had no problem. Why all of a sudden I can’t buy them? I have purchased gas and food today after multiple tries in game and had no problems with my card.
I called my bank and they told me to try to purchase gems again so they could see the transaction failing and try to push it through. While talking to them I tried again and the lady told me she isn’t seeing anything even show up on their end. She says it’s a problem with NCsoft.
As the user above has stated, I would like to buy these Limited Time offer character skins.