Thanks for letting us know, Len.
£5.05 is the difference between a full price adult peak single and the discounted off-peak single which you should have been charged. They seem to have missed that the full price adult single was capped at the discounted off-peak rate of £9.30 which also included your earlier journey in the opposite direction. I wouldn’t worry about it though – think of it as a little bit of compensation for the hassle.
What I will add for anyone else reading is that this was an unusual scenario. It is extremely rare for clocks to go out of sync, and even rarer for it to be more than 3 minutes. The grace periods at the start and end of the peak charging times are supposed to ensure that you are never overcharged. Clearly in this case something went badly wrong and the tech teams are working to ensure it doesn’t happen again. The only people who would have been affected were those touching in during the first minute or so after peak ended, which almost certainly included you. Many of those who might have been overcharged will in fact have capped anyway. Harsh though it sounds, I agree that refunds of this nature will be extremely rare, but I’m glad that we managed to secure it in this case.