Same with me, bought it at EB Games today and it doesn't show as a playable world, the content says it's installed but prompts me to switch to a different expansion disk to play the game, the code says it's not valid, and I'm out 20 bucks.
@ quietcanadian dragon valley is a world and shoud be in the +new game to start playing with the world, your game runs from whatever game disk or game download you installed last
http://answers.ea.com/t5/The-Sims-3-Store/FAQ-The-Sims-3-Store/td-p/333394
if after reading those threads does still not help then contact CS as only they can deal with code issues
They can be found here: https://help.ea.com/contact-us
Choose a category, a game and a platform for the contact options to show up.
If live chat is gray, change your country to US and make sure you're on US Business hours. It might also gray because they're very busy. Try later.
See this post if you have trouble with the site: http://sims3.crinrict.com/en/2012/10/how-to-contact-ea.html
