FAQ store worlds and how they there is a guide in there in how to redeem the codes in your the sims 3 account then download the world from there and install it ,
if you redeemed the codes in origin first then you may get or have an invalid/used code if that happened to your code you'll need to contact CS
once the world is downloaded and installed it will be in the main menu +new game to select the world to play in you will still play from whatever game you normally play from there will be no shortcut icon or launcher icon for the wold and it will not be in your origin my games tab
http://answers.ea.com/t5/The-Sims-3-Store/Guide-Sims-3-Store-Worlds/td-p/1589911
if in the event you need to contact CS
1.https://help.ea.com/en/contact-us/
2.Click on the orange NEXT button
3.Select a platform
4.Click on the orange NEXT button
5.Select a topic and describe your problem in a few words
6.Click on the orange NEXT button
7.Click Chat Now to chat with a Game Adviser
