Where to remove Leave a Reply?

I am using Simplify theme which is great.
I want to completely remove the LEAVE A REPLY section in all pages, so I deleted <? php comments_template(); ?> from single.php but the section is still there, why?

Thank you very much

You can see my website here: link

[contiued at https://wordpress.org/support/topic/where-to-remove-leave-a-reply-1?replies=2 ]