Solution that helped me today: forget about the credit card payment at Mogstation. That system rots. Try google Game Time Cards at Square Enix EU/NA store depending where u r, and you will find that there is actually a two month subscription Game Time Card costing not more than the normal price. Log in and pay and u will get instantly a 20 digits code. Log in Mogstation again input the code. Bang! It works. I feel it like a quest itself in the game. You receive all the items for veterens as well. Good luck!