Tips for successful purchases on gift cards.com via as portal?

I must have tried 10 or 15 different times, different payment methods, making sure my profile is accurate, etc. ​and still almost every single purchase of a Visa e-gift card except for one has been canceled within 3 or 4 hours of ordering. I've had one go through for a Visa, smaller ones for other store go through so I know there's at least some path through success but I can't figure out how to repeat it. Anybody have pro-tips?