Did you purchase the content with the same account you used to purchase CC4? This is very important.
If so, then the content should show up in Content Manager. So please first try clicking the Refresh button a couple of times and check the New Purchases again. If that doesn't make the content appear, please make sure you have the Pack tab selected in Content Manager and then do a search on the content pack name you purchased under All. This should find it and allow you to double click the thumbnail to install it.
Peter
Forum Administrator
www.reallusion.com