Comments plus not displayed

I'm using c3 theme http://themefuse.com/wp-themes-shop/clean-classy-corporate/
and after configuring the plugin... nothing happens.

Update: I added the missing code so now my theme looks like this:

<?php do_action("comment_form_before");?>
					<?php if ( get_post_meta($post->ID, PREFIX."_post_single_comments", true)!='true' ) { comments_template(); } ?>
                    <?php do_action("comment_form_after");?>

BUT the plugin doesn't render correctly. It looks like this: http://pbrd.co/U8zTlp