Did you just get that Visa e-gift card recently? The Visa e-gift card I got in December didn't allow me to use it to pay my Citi credit card bills as well. I was hoping that it might be an error pertaining to one card, but if you just got the card recently and it is still doing this, then it looks like the gift card issuer is cracking down on what you can use the cards for. It used to be that you can use the card for paying your Citi credit card bills.