AmEx Gift Card not Working

I've been having an issue where I cannot use my AmEx gift card on EA. It keeps saying "We were unable to verify your credit card or debit card. Please check your payment details and try again. Alternatively try another credit card or payment option or check with your card issuer or bank.". I'm buying an expansion pack and on the card I have more than enough to buy multiple packs so it's not a matter of funds. I also checked AmEx multiple times and the card is activated. I checked multiple other people's posts about this issue and they usually just get a reply that says hat cards EA authorizes, which is no help. Is it a problem where I don't need to put my name in? Does EA only take the 3 digit code on the back? Either way I've tried both and nothing worked. It really shouldn't be so hard to buy a pack. This has happened before, as I remember. 

( I think this is more of a problem with EA itself, but I'm trying to buy the Growing Together pack for Sims 4 incase that helps. )