Change user role if it's orders count more than

add_action('woocommerce_order_status_completed', 'wpa_120656_convert_paying_customer' );
function wpa_120656_convert_paying_customer( $order_id ) {
    $order = new WC_Order( $order_id );
    $user_id = $order->user_id;
    $customer_orders = get_posts(array(
        'numberposts' => -1,
        'meta_key'    => '_customer_user',
        'meta_value'  => $user_id,
        'post_type'   => 'shop_order',
    ) );
    if ( $customer_orders > 1 ) {
        update_user_meta( $order->user_id, 'paying_customer', 1 );
        $user = new WP_User( $order->user_id );

        // Remove role
        $user->remove_role( 'customer' ); 

        // Add role
        $user->add_role( 'dovclient' );
    }
}