Apologies for the delay in returning to make further comment. The joys of 100 hour working weeks and the need to sleep appear to have kept me away from FT. Fortunately I have a couple of days to catch up on the obligatory reading that I have missed on here.
The issue that made me quite angry was that BA clearly held a pre authorisation for ten days which was then released and recharged when a different rate was in force. Yes, it was my card providers rate, however, at the time of ticketing, the currency conversion shown by BA and my card provider were almost identical. The amount is not terribly important, it is the principle. The ticket cost was an absolute bargain and would be a bargain had the cost been another €1000.
My intention was not to sound like I was complaining, simply stating a matter of poor practice.
At the same time I made Avios redemption bookings on CX that were charged immediately. My assumption would be that I have a reasonable expectation to have been charged for a ticket that was issued at the point of booking.