Last Friday I got ridiculously drunk and managed to lose my 18+ student Oyster card (and my credit card... epic fail.). So while I waited for a replacement, I made use of a spare one that I had lying around, and put a few quid on it to keep me going.
Tuesday my replacement came. Kudos to TFL for dealing with it so quickly, I don’t think I could have received it any faster. However, I now had £8.50 on my spare account. I’ve had a card’s outstanding balance and the £3 deposit refunded before, but this time they wouldn’t refund me more than £2.50 on the balance. Panties. Oh well, I’ll use it up somehow.
So anyway, the lesson of the day is: don’t go overboard when topping up temporary cards. On the other hand, make sure you have enough on the card when you start travelling to qualify for the daily travel caps if you’re likely to travel that much on a single day, otherwise you won’t be eligible for the limit and will be scammed out of your backside.