WooCommerce get product Image from Category ID

I've been struggling with this all weekend I've read 100's of posts / tutorial but I can't seem to get this right. Basically I have a category ID and i want to get a random image on the category page for the category. E.g I have the category Jumper (cat id 1) and I want to get a random image from a post that is in cat id 1. At the minute i'm getting hundreds of the same image returned.

Here's the code I've created:

$args = array(
    'posts_per_page' => 1,
    'post_type' => 'product',
    'tax_query'     => array(
        array(
            'taxonomy'  => 'product_cat',
            'field'     => 'id', 
            'terms'     => $category->term_id
        )
    )
);

$myposts = new WP_Query( $args );

foreach ( $myposts as $post ) : setup_postdata( $post );

         $image = wp_get_attachment_image_src( get_post_thumbnail_id( $post->ID ), 'single-post-thumbnail' ); 
         //$image = wp_get_attachment_image_src($mypost->ID, 'woo-size-category');
         the_title();
         echo '<img src="' .esc_url($image[0]). '" alt="' . esc_attr($category->name).'"  />';
endforeach;

And Here's the whole content-product_cat.php:

<?php
/**
 * The template for displaying product category thumbnails within loops.
 *
 * Override this template by copying it to yourtheme/woocommerce/content-product_cat.php
 *
 * @author      WooThemes
 * @package     WooCommerce/Templates
 * @version     1.6.4
 */
if (!defined('ABSPATH'))
    exit; // Exit if accessed directly

global $woocommerce_loop;

// Store loop count we're currently on
if (empty($woocommerce_loop['loop']))
    $woocommerce_loop['loop'] = 0;

// Increase loop count
$woocommerce_loop['loop'] ++;

$thumbnail_id = get_woocommerce_term_meta($category->term_id, 'thumbnail_id', true);
$cat = 'no_image';
if ($thumbnail_id) {
    $cat = 'has_image';
}
?>
<div class="product-category product col-lg-3 element <?php echo $cat; ?>">



    <a href="<?php echo get_term_link($category->slug, 'product_cat'); ?>">

        <?php
        /**
         * woocommerce_before_subcategory_title hook
         *
         * @hooked woocommerce_subcategory_thumbnail - 10
         */
        if ($thumbnail_id) {
            $image = wp_get_attachment_image_src($thumbnail_id, 'woo-size-category');
            echo '<img src="' . esc_url($image[0]) . '" alt="' . esc_attr($category->name) . '"  />';
        } else {


$args = array(
    'posts_per_page' => 1,
    'post_type' => 'product',
    'tax_query'     => array(
        array(
            'taxonomy'  => 'product_cat',
            'field'     => 'id', 
            'terms'     => $category->term_id
        )
    )
);

$myposts = new WP_Query( $args );

foreach ( $myposts as $post ) : setup_postdata( $post );

         $image = wp_get_attachment_image_src( get_post_thumbnail_id( $post->ID ), 'single-post-thumbnail' ); 
         //$image = wp_get_attachment_image_src($mypost->ID, 'woo-size-category');
         the_title();
         echo '<img src="' .esc_url($image[0]). '" alt="' . esc_attr($category->name).'"  />';
endforeach;
        }

        ?>

        <div class="category-info">
            <h2><?php echo jwUtils::crop_length($category->name, jwOpt::get_option('letter_excerpt_cat_title', -1)); ?></h2>
            <?php if (jwOpt::get_option('woo_number_of_items', '1') == '1') { ?>
                <span class="count_items"><?php echo $category->count . ' ' . __('Items', 'jawtemplates'); ?></span>
            <?php } ?>
        </div>


    </a>


</div>

It would good to know the reason why this is not working. Any help would be greatly appreciated!

Thanks Chris

***** UPDATE - Here's the Var Dump *****

24array(1) { [0]=> object(WP_Post)#9805 (24) { ["ID"]=> int(12738) ["post_author"]=> string(1) "1" ["post_date"]=> string(19) "2015-02-16 15:27:06" ["post_date_gmt"]=> string(19) "2015-02-16 15:27:06" ["post_content"]=> string(80) "The Jungle Race is a serious event for Tiger. When the other animals don't train" ["post_title"]=> string(23) "The Tiger Who Was Angry" ["post_excerpt"]=> string(80) "The Jungle Race is a serious event for Tiger. When the other animals don't train" ["post_status"]=> string(7) "publish" ["comment_status"]=> string(4) "open" ["ping_status"]=> string(4) "open" ["post_password"]=> string(0) "" ["post_name"]=> string(23) "the-tiger-who-was-angry" ["to_ping"]=> string(0) "" ["pinged"]=> string(0) "" ["post_modified"]=> string(19) "2015-02-23 21:02:42" ["post_modified_gmt"]=> string(19) "2015-02-23 21:02:42" ["post_content_filtered"]=> string(0) "" ["post_parent"]=> int(0) ["guid"]=> string(0) "" ["menu_order"]=> int(0) ["post_type"]=> string(7) "product" ["post_mime_type"]=> string(0) "" ["comment_count"]=> string(1) "0" ["filter"]=> string(3) "raw" } }

Images are generated,but not from the right categories

******** SOLUTION ********

Here's what I ended up with (working!)

if ($thumbnail_id) {
    $image = wp_get_attachment_image_src($thumbnail_id, 'woo-size-category');
    echo '<img src="' . esc_url($image[0]) . '" alt="' . esc_attr($category->name) . '"  />';
} else {

global $wpdb;

// Get a random product from this category
$args = 'SELECT object_id
FROM `wp_term_relationships`
where term_taxonomy_id = '.$category->term_id.' order by rand() limit 1';

$random_product_in_cat = $wpdb->get_var( $args );


// Get the returned post thumbnail
$image = wp_get_attachment_url( get_post_thumbnail_id($random_product_in_cat) );
echo '<img src="' . esc_url($image) . '" alt="' . esc_attr($category->name) . '"  />';
}

I'd create an array of posts via get_posts(), and then choose a random one. I haven't tested this, but here's the concept:

// Get a random product from this category
$args = array(
    'post_type' => 'product',
    'posts_per_page' => 1,
    'category'  => $category->cat_ID,
    'orderby' => 'rand',
);
$random_product_in_cat = get_posts( $args );

// Get the returned post thumbnail
echo get_the_post_thumbnail( $random_product_in_cat[0]->ID, 'thumbnail' );