[Plugin: Arconix FAQ] Shortcode before content

I use the shortcode to insert Acronix Faq into a page. My issue is that it always shows before the content, on top of the page, even when I place the shortcode after the (text) content.

This is the page I’m working on:
http://boooth.me/veelgestelde-vragen/

I already googled the issue and found out it had to do with using the echo command. But I’m definitely no coder so I need someone to help me out, showing me exactly where to edit the code.

Thanks in advance!

http://wordpress.org/extend/plugins/arconix-faq/