Giles Yeah, that would be a reasonable circumstance. Obviously, there is an element of discretion involved, but under normal circumstances (ie. not gaming the system) you'll get a no-quibble pro rata refund.
We may well need to revise those terms, depending how people are using it. I'm sure you understand. As an example, we may for instance need to restrict the number of refunds of an annual plan to one a year.