In message
, at
14:43:22 on Sun, 23 Nov 2008, MIG
remarked:
It's about as conceivable as it being impossible for refunds or auto
top-ups to be trigged by anything other than making a journey on LU.

Are you under the misapprehension that all top-ups need a LU trip to
trigger them? All that's required is one such trip to convert a card
into an auto-topup card.

The reason for doing it at a particular station could be in order to get
you on CCTV at a known place, as an anti-fraud measure. Imagine someone
stole your credit card details, then set up an auto-topup onto their
Oyster from your account.
--
Roland Perry