According to a news post on the official Phantasy Star Online 2 (JP) players site Monday, SEGA will be discontinuing their acceptance of American Express cards for AC purchase in the near future. Players who have purchased pre-paid AMEX cards for the purpose of buying AC should consider using them before this change takes effect.
In the future, only Visa, Mastercard, and JCB will be excepted for AC purchases. This change is likely related to steps SEGA has been taking to add further authentication measures to their online payment processing, though exact details are still unknown. A big thanks to Mike for posting the news in our forums!
Update 10/25: According to a new post on the official PSO2 JP players site, this change is now in effect and American Express will no longer be accepted.
vBulletin Message