If the train you intended to travel on was delayed and you decide not to travel, you may return the unused ticket to the original retailer or train operating company who sold you the ticket. You are entitled to a full refund.
All refund requests must be made within 28 days of the ticket expiry date. If you have a physical ticket this will need to be returned to the retailer of the ticket in order to obtain a refund
If you purchased your ticket from another train operator or another ticket retailer then you will need to contact them directly in order to obtain your refund.