The AT&T C105A (Galaxy S4 Zoom) owners need to raise some hell as both Samsung and AT&T are lying about what Android version it has. They officially list it as having 4.4 KitKat. It does not have 4.4 KitKat and cannot even be updated to 4.4 KitKat at this time. Under many state laws this constitutes false advertising and is grounds for legal action.
The possible claim of "Samsung never built updates for the SM-C105A" cannot be taken at valid either, as TelCel (Mexico) has sent out at least two updates to their SM-C105A.
Samsung Official Specs as of July 17th 2014
AT&T Official Specs as of Sept 2nd 2014 (older versions will not load for some reason)
Inaction gives the impression that not supporting a device and listing false official specifications is OK. So if you do not want this type of bait and switch to keep going on, post on AT&T's and Samsung's G+ & Facebook pages, and tag them on Twitter. Let them know about how this is unacceptable and the SM-C105A needs to start receiving updates to 4.4 KitKat immediately.
This may not be a U.S. only issue. So if you have a S4 Zoom and are not on KitKat, use web.archive.org and check to see if they did the same in your region