How to auto update this theme? for the price of $61 I thought that this theme has auto update where i just need to put my purchase code and it will prompt update on new release.

I just bought the theme and install the demo content. It is not like the one on the demo the pages are messy and elements are out of place. The Visual Composer is out of date so i thought it is the culprit. How do i update and how do i fix this?