The 13.1.2 update will not be available on the product update page because it is a feature bearing update only available to Creative Cloud subscribers.
Jonathanearthsleep you will want to review the install logs to determine the exact failure you are experiencing when trying to apply the update. You can find information on how to review those logs in the document referenced by Mandeep in message #1 or by reviewing Troubleshoot with install logs | CS5, CS5.5, CS6 - http://helpx.adobe.com/creative-suite/kb/troubleshoot-install-logs-cs5 -cs5.html.
