London Transport have bugs in their Oyster system. I can be certain of this because
- I keep my Oyster card in my wallet at all times
- My wife has her own Oyster card (so has no need to use mine).
- No other people live in the house or have access to my card
- They have taken money against my account on days when neither of us was in London.
But whilst the ticket offices can print off a transaction history going back months (entitled Oyster Usage Statement), the Oyster management process only holds the last few weeks of data. This means that if the transaction is more than a few weeks ago, they will not do anything to correct it. So say goodbye to your hard earned money.
So, if like me you are an occasional user of the Oyster card (to get the fare benefits and convenience) – but also want to make sure Oyster mistakes aren’t stealing money from you; then you must log on to your account every few weeks in order to check for phantom entries.
If you do not, their minimal data retention means that they won’t entertain any claim, even though other parts of the system have the data.