WooCommerce hide refund reason from customer

functions.php

<?php
/**
 * Replace refund reason with generic Refund text.
 *
 * @param $total_rows
 * @param $order
 * @param $tax_display
 * @return array
 */
function remove_public_facing_refund_reason( $total_rows, $order, $tax_display ) {
	foreach ( $total_rows as $id => $row ) {
		if ( false !== stripos( $id, 'refund_' ) ) {
			$total_rows[ $id ]['label'] = __( 'Refund' );
		}
	}
	return $total_rows;
}
add_filter( 'woocommerce_get_order_item_totals', 'remove_public_facing_refund_reason', 10, 3 );