谁能解释下为何美国本土的借贷卡也会购买失败？

classmas

下午下单，是在美国的亲戚，59.99+4.8=64.79美刀，今天晚上突然给我来一封邮件

Greetings,

This notice is being sent to inform you that we were unable to successfully complete your recent purchase on the Blizzard Store.  The charge for that item on your order was not finalized.

Since we could not fully authorize this item’s purchase, it has now been deactivated.  If it was applied to a play account, it will no longer appear, and the account will be left in the state it was in previously.

For any questions about Blizzard orders or your Blizzard Account, please find the contact information for our Blizzard Billing and Account Services department at http://su.battle.net/support/en/artcle/contact

We thank you for your patronage and your patience in this matter.

Regards,

Customer Service
Blizzard Entertainment
http://us.battle.net/en/
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人是绝对信得过，就是不明白，他的卡是 美国本土的。有没有人遇到同样的问题？