Thanks so much for your reply. Sadly I don’t think that either of those work-arounds will work. My client doesn’t want to manually change bookings as there will be too many of them and it’ll take him too much time. Also, they may need to change names several times so that rules out refunding and rebooking too. Such a shame - it may be that they’ll need to buy in a pre-existing booking system and link out to it (something they didn’t really want to do as they wanted to contain it within the site and do it themselves. It’s disappointing as I really extolled the virtues of Wix and all that it can do - I build sites all the time and haven’t come across many things that it can do!
Interestingly also (and completely off-track), my brother’s fiance has the same surname as you! What a coincidence 
Thanks again for your help
Miranda