So I just got an iPhone again after a short stint with Android. I tried to add my credit card to Apple Pay, but it failed at first. I've googled and tried everything. Rebooting, changing my passcode, reinstalling the OS, signing in and out of iCloud, and readding it, but I can't add the card. It doesn't show up on iCloud.com, and the phone acts like no card has been added. It's a Discover card. Any ideas?