First of all, your template lacks tons of key features such as proper typography and alignments (margins, paddings and so on).
Secondly, it’s way too redundant and simplistic. It has nothing else apart from a homepage and a help page.
Moreover, it’s not intuitive. At first you are expected to simply scroll down to see more content. Then you realise you have to use the tabs which when used, you are left with no option to go back without clicking the ‘Go Back’ button in your browser. It is confusing to the end-user.
Additionally, I am not sure how properly written the documentation is but as far as images from Envato authors being used in the template are concerned, you are NOT allowed to re-sell them under no circumstances and in any way unless you have a separate in-stock re-sell licence agreed upon with the original author.
Extended licences do NOT automatically give you the permission to re-sell assets bought from Envato in any way.
Learn more about in-stock licences here.
I guess you should try a new approach to the template because it’s a hard reject.
P.S. Personally, I believe that the fact that you received no specification of what’s wrong means that perhaps everything is wrong.
I hope you take my advice under consideration.