Re: cant use my sims 3 dragon valley key

is your game up to date with the newest patch ? is origin updated ?  did you get two codes a 16 digit and 20 digit 16 digit code is for celtic lands 20 digit code is for dragon valley

guide to worlds with some common issues and what to do http://answers.ea.com/t5/The-Sims-3-Store/Guide-Sims-3-Store-Worlds/td-p/1589911

if you do have an invalid code contact CS since this is a public forum we cannot help you since it would involve accessing your account

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