SEO and UpFront - websited not indexed by Google anymore

Hi There,
A few months ago, one of the users contacted me to complain about the fact that his website is not indexed in Google.
I added the website to Webmaster Tools, validate it, added both versions (with and without www), submitted a sitemap... Nothing. Even after a few weeks, same thing.
Then I got the second complain - another user, same issue.
Was the moment I said I'm going to use Webmaster Tools to submit the websites to index. While fetching as google, I noticed that the content of the website is actually not visible to the search engine. It only sees the first section, the full screen section which contains the title.

So, even if I submit to index, Google will not index pages with just a few words in them - Not sure what is wrong - I tried with background image, slider, same thing. Now, after trying to fix this myself for a few months, I said maybe it's time to flag this and hope to get some help from the community.

Thank you.