Got a new debit card and needed to update my info from the card and when I get to the portion to where the screen should be asking me to input everything, I just get the Blizzard Hourglass icon that doesn’t actually load the next page. I’ve tried different browsers, turned off any ad-blockers, ect. Same result.
What gives?
Have you tried clearing ur cookies and cache. if that doesnt work open a ticket to billing to get it sorted out.
I’d agree with Darthwraith, try clearing your browser’s cookies/cache. I’d also ask, are you editing your current payment method of adding a new one? I know we had some issues with updating an existing payment method so I’d try deleting the old one entirely and adding the new one.
I deleted my old info (since I saw no means to edit current info since all it was needing done was an expiration date/CVV2 change) and even trying to add a subscription or add a payment method has the same result.
You might try on a mobile browser on a mobile network instead of your home network in case something on your network went wonky, or some security setting on your computer got changed somehow in a recent update.
Tried on my phone, keeps saying something has gone wrong. There’s got to be something going on over on Blizzards end of things, not mine.
Is your phone on the same wifi as your computer?
In situations like these, it can indeed be on Blizzard’s end, but it’s extremely rare. You can always reach out to Billing to see if they can lend a hand or shed some light too 
https://us.battle.net/support/en/help/product/wow/166/180/channels
I’d recommend Live Chat.
I have a problem similar to yours, my card and billing were just fine, I’ve been paying with the same card for two consecutive years, and out of the blue my payment method just wasn’t working anymore. I tried clearing my browser’s cookies, using another browser, another internet conection, my phone, another PC, etc… well I tried everything… I even got in contact with support, they tried to blame my bank, but my card is ok, so they excluded my old payment method, and now I got none, but still can’t add a new one. Always with the same message: “An unexpected error occured”, and just refresh the screen to add my card info again…
In a case like that, the first recommendation I’d make is to manually clear all payment methods, and readd - even if it is the same card and same info.
As I said before… I’ve already done that, your web system just refresh the screen, and don’t let me add another payment method. And I already tried: clearing my browser’s cookies, using another browser, another internet conection, my phone, another PC, etc…
Maybe check after maintenance?
Unless you have something blocking the page or functionality on the page, not sure. Could be security software, blocking cookies, etc.