I had a similar problem going on. I had a custom post type Vacatures which I wanted to display with a page-vacatures.php.
But the layout was completely messed up. After digging through every file in my theme, I figured out that the webpage used archive.php.
Setting 'has_archive'=>false solved my problem because WordPress wouldn’t search for an archive file but for the template file (page-vacatures.php) that I specified.
@Rinoleti: Have you tried saving your permalinks again? After changes to a link I always save the permalinks again because WordPress can do weird stuff after changing a slug or something like it.