How about page? is that simple page o custom content type?
Have you enabled wpDiscuz for all content type in wpDiscuz Settings > General tab?
Also please deactivate wpDiscuz and make sure the default comment box also doesn’t exists on that page.
I’m sorry but if you’re not familiar with WordPress theme you have no real chance to debugg it and find solution. We can’t provide site and specific individual support for such a deep debugging and problem fixing. We’re getting dozens of support requests per day and that’s become physically impossible.
First edit the page and find the template it uses, screenshot:
https://screencast.com/t/oXEyjvIsm
If it use the default page template you should search for page.php file in template folder. If it’s not the default template then you should fined some file with page- … prefix and similar name, e.g. page-contact.php or page-full-width.php or so.. the content of page template file should content such code:
<?php
/**
* The template for displaying all pages
*
* This is the template that displays all pages by default.
* Please note that this is the WordPress construct of pages
* and that other 'pages' on your WordPress site will use a
* different template.
*
* @package WordPress
* @subpackage Twenty_Twelve
* @since Twenty Twelve 1.0
*/
get_header(); ?>
<div id="primary" class="site-content">
<div id="content" role="main">
<?php while ( have_posts() ) : the_post(); ?>
<?php get_template_part( 'content', 'page' ); ?>
<?php comments_template( '', true ); ?>
<?php endwhile; // end of the loop. ?>
</div><!-- #content -->
</div><!-- #primary -->
<?php get_sidebar(); ?>
<?php get_footer(); ?>
it may be very different but you should check for <?php comments_template( '', true ); ?>
function.