Wordpress - sub page link reverts to Home page - php

Question

I'm building a site on Wordpress and using html5blank theme for the first time. I have a number of sub-pages I need to add as links from one of the main pages.
On of my main pages is titled 'Agency' and within the agency page I have a number of images which act as links to a number (7) of sub-pages -
I've created the sub-pages on my dashboard with Agency as the parent so the link I get for the first image is ...site-name/agency/2k4kproduction . Here's the code for the links. So far I've only converted two of the links (2k4k and adhoc) -
<div class="twelve columns agencyproducts">
<p>WHAT PRODUCT ARE YOU INTERESTED IN?</p>
<a href="http://localhost:8888/agency/2k4k-production/"><figure>
<img src="http://localhost:8888/wp-content/uploads/2017/07/production.png" alt="Production">
<figcaption>2K / 4K PRODUCTION</figcaption>
</figure></a>
<a href="postproduction.html"><figure>
<img src="http://localhost:8888/wp-content/uploads/2017/07/post-production.png" alt="Post-Production">
<figcaption>POST PRODUCTION</figcaption>
</figure></a>
<a href="2d3danimation.html"><figure>
<img src="http://localhost:8888/wp-content/uploads/2017/07/animation.png" alt="Animation">
<figcaption>2D / 3D ANIMATION</figcaption>
</figure></a>
<a href="http://localhost:8888/agency/adhoc/"><figure>
<img src="http://localhost:8888/wp-content/uploads/2017/07/ADHOC.png" alt="ADHOC">
<figcaption>ADHOC</figcaption>
</figure></a>
<a href="interactive.html"><figure>
<img src="http://localhost:8888/wp-content/uploads/2017/07/interactive.png" alt="Interactive">
<figcaption>INTERACTIVE & PERSONALISED</figcaption>
</figure></a>
<a href="tvadverts.html"><figure>
<img src="http://localhost:8888/wp-content/uploads/2017/07/tv-adverts.png" alt="TV ADVERTS">
<figcaption>TV ADVERTS</figcaption>
</figure></a>
<a href="360video.html"><figure>
<img src="http://localhost:8888/wp-content/uploads/2017/07/360.png" alt="360 Video and VR">
<figcaption>360 VIDEO & VIRTUAL REALITY</figcaption>
</figure></a>
</div>
For my text files I've titled them page-agency-2k4kproduction.php and page-agency-adhoc.php which is what I believed to be the correct naming convention as per the template hierarchy. However, when I click on these links they revert to my home page. I've no idea why this is not working as my agency file/page works fine as page-agency.php so I'm not sure why this will not work. Any assistance appreciated.