post_content is not showing form called by [clean-contact]

I m using Clean contact in contact page using the short code: [clean-contact]
Its working fine in the page and sending emails. https://www.designabz.com/contact/
The problem is, When i am trying to call the contents of the contact page to ‘index.php’ by using ‘post_content’ , the contact form is not appearing.
only showing [clean-contact] in the space of contact form.
https://www.designabz.com/#contact

Code I am using

<div class="contact">
<?php
$post_id = 31;
$queried_post = get_post($post_id);
$title = $queried_post->post_title;
?>
<div class="title"><?php echo $title; ?></div>
<div class="content"><?php echo $queried_post->post_content; ?></div>
</div>

I am new to WordPress! please help!