How can I get The Sims 3 for Mac if I buy it for Windows on Steam?

This is forum is origin not steam and they dont mix. From what I heard steam does not sell the Mac version but double check with steam. You may be able to transfer your steam to origin but you would have to contact EA directly for that

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

@ravip8975 

try this and see if it'll work for you downlaod the mac version of orign redeem your codes there

tips from caspinwall ty

Download and install the Origin client for Mac and make sure it is up-to-date. If you already have Origin on your Mac but are having problems with downloading or installing games, delete the client and download a new copy (this sometimes fixes issues with downloading). The latest version can be downloaded from here: http://www.dm.origin.com/mac/download

Additional advice on how to download games (thank you Tremayne for this tip):
When downloading from Origin, do NOT use the first install icon. Move your cursor over the game cover and click on the information (letter i) and then click on the install button from there. For some reason, downloads from Origin frequently become corrupted.