16 digit codes are usually for DLC content on the sims3 site hmmm but there was an issue where some people where getting a 16 digit code for the game which was some sort of error
see here for more info http://answers.ea.com/t5/The-Sims-3/IMPORTANT-Invalid-16-digit-codes-on-DVD-Version/m-p/2074321#M105187
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 Advisor
guide on how to contact CS
http://answers.ea.com/t5/Beta-Archive/How-to-contact-a-Game-Advisor-using-the-new-EA-Help-page/td-p/2161281
