Pre ordered album not showing

I pre ordered the new gorillaz album, they released 6 songs before the big album drop. I have those six songs but the rest of the album that I purchased is not downloading. I looked in hidden and I've synced it with a computer and it's nowhere to be found. It says I can purchase the rest of the album and I have the iTunes money to do it but when I start downloading it I get a notification that my credit card has expired and won't let me complete the purchase, but I'm not buying with my credit card I'm getting it with and iTunes gift card. So what should I do?