I had two tickets, however I had to change the times. This meant a different price. No problem. Cancel the tickets and buy more. So got an email about the refund, bought more tickets and sent the original tickets to Edinburgh. So far so good. My refund was less than half the email promise. Despite repeated calls they will not entertain the idea that a mistake has been made by them. I have no evidence of what was in the envelope that I returned. I have no idea how this is possible without going to a legal professional. Do not trust Trainline. It seems that they feel able make promises, but not keep them.