Do they not show in Origin when download the Origin client and log in ?
You should be able to reinstall from there. No need to rebuy.
If they don't show up there, you need to contact customer Support
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
Beware that there's no longer an Email option
