TOEFL registration

Having difficulty registering for the October 12 test session @ my old Alma Mater.
I've tried my brother's credit card, my fiancee's as well as her dad's! And it's all giving me an authorization failed every single time!!!! I know I might have made a mistake when I used my brother and my girlfriend's credit cards (Yes I asked permission from them), but when I used my gf's father's card, it was still the same.................

This is really bumming me down..