I was travelling from new cross to Euston by bus which involves two buses, this counts as one fare on oyster if you touch in on second journey within a certain time. I touched in on first bus and forgot to on second bus. I got stopped shortly after getting on the second bus and explained That I had tapped on first not long before. They said they couldn’t check so fined by penalty notice £40. I appealed on the basis that they had not incurred a loss as my fare had been paid on first bus. They have rejected my appeal. How can they fine me if I have paid for the journey ?, there has been no loss. Can anyone advise ?