OK - I own up.

I have a Zone 2 annual season ticket. I found that this allowed me to
run my journey from a Zone two station, through Zone 1, and back out
of a Zone 2 station no problems since October. Much like the old
paper ticket.

Now Pre-Pay is up and running - it deducts £1.60 each time (the
extension amount). This is going to cost more than buying a Zone 1 & 2
Annual Pass.

My question is: If I upgrade and add Zone one - will they allow this
without penalty fares for the three months of 'unofficial' use?
Will I be retrospectively charged extensions for all the journeys
made?
What If I ask for a refund on the season ticket - and then get a new
full zone season ticket? Will they deduct the due amounts from my
refund?