iTunes Album Artwork

I purchased an album off of iTunes today. When I listened to the album the first time the cover artwork showed up both in the music library and on the individual songs, however when I returned to listen to it again all of the artwork was gone. I've tried asking iTunes to re-download the artwork several times, but nothing has changed. I am afraid of trying to remove the download and re-downloading it because I've heard that in some cases the music must be re-purchased. I've even gone back to the iTunes Store and found the album (which displays the cover art) and tried to play it from there, but the cover art still won't show up for my download. Finally, I've tried restarting my computer, but the artwork still won't show up.

How can I get the cover art back? Is there any way other than deleting the album? If I must delete the album how can I do so in a way that I don't have to re-purchase it?

Thanks in advance for the help.