Your Flight Credit is the full and final amount of the booking you were refunded for, so it cannot be exchanged for cash.
Flight Credit valid for 18 months from the date of issue. The Flight Credit can be used to book available flights until it expires. It can be used once or several times until the balance runs out. The Flight Credit is not personal or granted to a particular person and can therefore be used to make bookings for the recipient or another person. You can check the available Flight Credit balance when you make a new booking and reach the payment page. If there is not enough Flight Credit to cover the total price of a booking, the remaining amount must be paid by card. Valid for all fares and any additional services booked. It can be used in conjunction with resident and large family discounts. If the price of original booking, or part of it, was paid with a discount code, the discounted amount will not be refunded, which means that it will not be included in the Flight Credit. If the booking or part of it was paid with Avios points, these will be refunded to your Avios account.