Ewan – I found them on the trainline.com I don't think they would be flexible but I think there was a later one. That was singles rather than returns. I think valid for the booked train only.
Ewan – its just ridiculous. Cheapest single was £28 out and £35 back The outward one was a bit too early – some stupid hour of the morning at Woking. the one back awas at 3 m but I think there was a £35 at 4 pm as well.
Its always worth checking for two singles rather than return