Custom post type single page

I have created a custom post type called kundcase.
I have a file called: kundcase.php where the first kundcase is shown with following code:

// Set the page to be pagination
$paged = get_query_var('paged') ? get_query_var('paged') : 1;
// Query Out Database
$wpbp = new WP_Query(array( 'post_type' => 'kundcase', 'posts_per_page' =>'1', 'paged' => $paged ) );

In the widget I created a want to show the four latest cases, and that works fine as well.
Theese cases are linked to a single page like: domain/kundcase/customer and there is where the problem begins.
What do I do to get the same layout as the kundcase.php.
I have tried to create a single-kundcase.php but it is ignored.

The code that echos the cases in widget:

// Set the page to be pagination
$paged = get_query_var('paged') ? get_query_var('paged') : 1;

// Query Out Database
$wpbp = new WP_Query(array( 'post_type' => 'kundcase', 'posts_per_page' =>'10', 'paged' => $paged ) );
?>

<?php
// Begin The Loop
if ($wpbp->have_posts()) : while ($wpbp->have_posts()) : $wpbp->the_post();
?>

<?php
?>
<li>

<?php // Output the title of each kundcase item ?>
								<h2><a href="<?php the_permalink(); ?>"><?php echo get_the_title(); ?></a></h2>
<p><?php echo get_the_excerpt(); ?>
</p>
<p><a href="<?php the_permalink(); ?>">L?s mer...</a></p>
								</li>

So what do I do? Is it not possible to combinate kundcase.php and single-kundcase.php? Or do I use the wrong way/code for the output?

Would be greatful for some help with this.

/Malin