The Live eftpos Payment Gateway supports automatic refunds inside WooCommerce. Please refer to https://docs.woocommerce.com/document/woocommerce-refunds/ for details.
The Reference ID of the refund transaction is also logged under 'Order Notes'.
Note: For accounting purposes, if taxes are enabled the refund must be processed per line to separate tax amounts. Therefore, merchants will not be able to enter the refund amount without adjusting the product quantity if the ‘Enable taxes’ configuration checkbox is ticked.
This setting can be found at WooCommerce > Settings > General (Reference: https://wordpress.org/support/topic/refund-amount-field-grayed-out/)
Service fee for refund transactions
Refunded transactions are similar to regular sale transaction in that they attract a service fee. The service fee will be debited from the total amount payable to the merchant.