Don’t expect any customer service
It is an ok service if you get everything right and book tickets through them. We spent 3 days trying to upgrade our tickets and couldn’t. You can’t call anyone and responses are slow. I gave up with them in the end. It’s an internet company with no customer service and their mark up is probably quite expensive for what you get . I tried using their numbers and online chat but after three days I gave up. They just don’t help resolve matters. You can buy tickets direct, then if you need to make changes, this can be done at the station where the staff are helpful, if you use an agent like I did , then they say you have to contact the agent. I have now read their reply , and as expected they are advising I do all the things a tried to do.