/**
 * Cancela o pedido pendende depois de algum tempo
 */
function cancel_pending_order_after_x_days() {
    $limit = 4;

    global $wpdb;

    $expired_payment_orders = $wpdb->get_col($wpdb->prepare("
            SELECT posts.ID
            FROM {$wpdb->posts} AS posts
            WHERE posts.post_status = 'wc-pending'
            AND posts.post_date < %s
    ", date('Y-m-d H:i:s', strtotime('-' . $limit . ' days'))));

    if ($expired_payment_orders) {
        foreach ($expired_payment_orders as $order) {
            $order = wc_get_order($order);
            $order->update_status('cancelled', 'Pedido foi expirado.');
        }
    }
}

// Agenda a verificação
function init_cancel_pending_order_after_x_days() {
    if (!wp_next_scheduled('schedule_cancel_pending_order_after_x_days')) {
        wp_schedule_event(time(), 'daily', 'schedule_cancel_pending_order_after_x_days');
    }
}
add_action('init', 'init_cancel_pending_order_after_x_days');

// Excecuta a verificação
add_action('schedule_cancel_pending_order_after_x_days', 'cancel_pending_order_after_x_days');