dB wrote:

The paper vouchers are inconvenient for those of us who do regularly use the
underground, so why don't they give people the option of chosing their
preferred method of refunds?

They used to but they seem to have stopped (I've certainly received
discounts as Oyster Credits on one occasion). Presumably it caused
some problems.

--
Each day a man watched a donkey walk past a high wood fence with one
plank removed. Each day he saw a nose, then the ears, then the neck,
forequarters, back and finally the tail. He pondered this for a time
and eventually declared. “I understand now. The nose causes the tail”