Graham Hick wrote:

This happened to me last night and I was wondering if anyone
else had come across it. I was topping up my Oyster pre-pay
card at the touch-screen ticket machine at North Greenwich,
using up all the small change in my wallet. After about £7,
the machine closed the coin slot, and threw all my coins back
into the rejected coins/change tray. It sounded like I'd won
the jackpot at Las Vegas!
....
Not a major grumble, but a bit of a "head scratcher" - why was
this feature designed into the system in the first place?

Graham

A pure guess, but maybe it has to keep the coins in a holding area in
case you press cancel, and you'd filled it up?

Colin McKenzie