Just before Max's lecture, I was asking Jon Allen and SK how long it took to get a refund from London Underground under the Customer Charter. It seemed to be anything from weeks to months and in some cases ones from the post appeared to disappear completely. Then lo & behold, mine arrived in the post yesterday.
Anyway I'm pleased that LU very much regretted letting me down "on this occasion", although it was a shame no one at Hammersmith felt the need to be so polite on the day. Will definitely bookmark the very well hidden refund page on the TfL website for the inevitable future occasions when they let me down.