Mizter T wrote:

The fact that refunds are available for erroneous Oyster charges is no
secret at all, it is mentioned in plenty of TfL publicity and LU staff
will readily refer you to Oyster customer services if you have
concerns about overcharging.

The fact that the system is designed to levy erroneous charges is news
to me, though (and I suspect other occasional Oyster users, too).

If I were to enter a station and then leave without travelling, I would,
naively, expect one of two things to happen:

(1) My card operates the gate and doesn't charge me anything, having
understood that I haven't made a journey; or

(2) The system doesn't understand what has happened, so my card doesn't
operate the gate and instead flashes up "Seek Assistance".

What I would not, naively, expect is that the gate pretends to do (1)
but in fact charges me an (AFIACT) unpublished fee for failing to make a
journey.

I'm quite sure that this is due to poor design rather than malice on the
part of TfL, but that doesn't make it right.

-roy