I want to start off by saying this is most likely in the wrong forum, so any mods, feel free to move it if it is.
Anyways, to the problem itself. I am trying to donate to Optifine for the awesome cape (and to support them). I am having issues though. The Optifine donation page allows PaymentWall to be used, which within PaymentWall allows the use of Visa Cards. I currently own a United States of America Vanilla Visa Prepaid card which has enough funds to pay for the donation. When I put in my car information though, it just says could not authenticate. Any help please?