http://mobilesyrup.com/2013/10/18/samsung-begins-international-rollout-of-galaxy-s4-android-4-3-update/ Found a thread here. One of the comments has a legit answer/explanation why you're still not receiving updates.
Zedge is a good application for this. (Download here)"For years ZEDGE™ has been the most trusted and popular source of free ringtones and wallpapers in the world."
