posts_nav_link does not show, need alternative?

I made this custom template to show several posts that belong to 1 category.. It went prett well and the posts actually show.
I styled them to my wishes and was a proud man.

That is until I figured I needed to add the navigation, since at 10 posts the page will have reached its limit.
Now i have 14 posts, and well.. 4 disappeared. The posts_nav_link function just refuses to show up.

I will PM you the weblink (googlebots)

See my code below:
[Code moderated as per the Forum Rules. Please use the pastebin]

edit – i am using the following plugin to get the category posts on that single page:

List Category Posts is a simple WordPress plugin which allows you to list posts from a category into a post/page using the catlist shortcode. This shortcode accepts a category name or id, the order in which you want the posts to display, and the number of posts to display. You can use catlist as many times as needed with different arguments. Great to use WordPress as a CMS, and create pages with several categories posts.