function mynew_product_subcategories( $args = array() ) {
	$parentid = get_queried_object_id();
	$args = array(
	    'parent' => $parentid
	);
	$terms = get_terms( 'product_cat', $args );
	if ( $terms ) {   
	    echo '<ul class="product-cats">';
	        foreach ( $terms as $term ) {              
	            echo '<li class="category">';                        
	                woocommerce_subcategory_thumbnail( $term ); 
	                echo '<h2>';
	                    echo '<a href="' .  esc_url( get_term_link( $term ) ) . '" class="' . $term->slug . '">';
	                        echo $term->name;
	                    echo '</a>';
	                echo '</h2>';                                                        
	            echo '</li>';                                                        
	    }
	    echo '</ul>';
	}
}
 
add_action( 'woocommerce_before_shop_loop', 'mynew_product_subcategories', 50 );