Get orders of a specific customer woocommerce

Try using wordpress get_posts() instead

$user_id = 22;
$orders  = get_posts( array(
  'meta_key'    => '_customer_user',
  'meta_value'  => $user_id,
  'post_type'   => 'shop_order',
  'post_status' => array_keys( wc_get_order_statuses() ),
  'numberposts' => -1
));

echo '<pre>';
print_r( $orders );
echo '</pre>';