Stuff

<?php
wp_reset_postdata();
$cat = get_query_var('cat');

$query = new WP_Query(array('post_type' => 'post', 'cat' => $cat, 'posts_per_page' => 4, 'paged' => get_query_var('paged')));

if ($query->have_posts()) : while ($query->have_posts()) : $query->the_post();
        ?>    
        <div class="service-box">
            <!--box 3-->
            <div class="product-box">
                <div class="product-image-box">
                    <a href="<?php the_permalink(); ?>"><?php the_post_thumbnail('test'); ?></a>
                </div>


                <div class="product-box-text">
                    <h5><?php the_title(); ?></h5>
        <?php the_excerpt(); ?>
                    <div class="product-more"><a href="<?php the_permalink(); ?>">...more</a></div>
                </div>

            </div>
            <!--/box 2 -->
        </div>
        <!--/service box -->
    <?php endwhile;
else: ?>
    <p><?php _e('Sorry, no posts matched your criteria.'); ?></p>
<?php endif;
wp_pagenavi();
wp_reset_postdata();
?><br/><br/>