I am using a Visa card to try to buy a pet. It's the same Visa that is already on my account and doesn't expire for 2 years yet. However, my CC Co. upgraded me to a gold card, which has the same number but a new expiry and CVV.
After putting a pet in my cart and hitting checkout, I went to the "enter your CVV" screen, did it (off the new card) and clicked through, got to the final screen and hit "Buy". It said my card data was wrong, and kicked me back to
It did it real fast, so my hunch is it didn't even query the VISA clearinghouse, it was locally comparing the CVV I entered (or its hash) to the one on file. I could be wrong. Bug #1?
The first purchase, I selected "Use another card" and entered ALL the information for the new version of the same card's information again. And it took that.
Then I decided to buy Li'l XT also. Came to the checkout screen, couldn't really tell if it was looking at my new card or my old one. Put in the (new) CVV, and FAIL. Back to the screen.
OK, so I pull down the litle menu that lists all my cards. The same card is listed twice, as "VISA 0000" and "VISA 0000" again, bug #2. OK so I selected the other one and tried the CVV again. So I picked the first one again. Fail. Second one again. Fail. First again. First AGAIN (in case it is switching them each time). Fail fail fail.
OK so I into account settings at https://us.battle.net/account/management/wallet.html ... there's the offending card, and below it, the new card. I delete the >>OLD<< one. I refresh, and it now lists ONLY the OLD one. Yes, I'm sure I deleted the right one. Maybe your software is going "User requested "delete card VISA 0000" and sending that signal to other software that deletes the first one it sees. Whoops, bug #3.
That didn't work, so I delete all the cards, and add my new card. OK now it is the only one listed, and that is correct. Back to the pet store.
Rinse wash repeat, enter CVV, FAIL. I go back to the previous screen, and it lists TWO of the "VISA 0000" entries again.
So I hit "Reset Safari" and wipe out my cookies (and two forum posts I was writing elsewhere, ouch.) Restart my WoW launcher to get back to the ad, click through, back to buying Li'l XT, my cart is empty, add to cart, checkout, take defaults, enter CVV, and -- fail.
I go back to the previous screen, and it lists TWO of the "VISA 0000" entries yet again. Remember, I deleted the other in accounts. Bug #4? I only know one CVV (off the new card) and again, iterating on each option does not work.
Look, this is just bugged/broken. The triggering event seems to be my CC Co. issuing me a new card with a new expiry and CVV, well before my old card expired. I feel like I'm banging my head against the wall, you know the feeling.
Time to document and tell Blizz. Hope this helps.