Munnyspinner
Do you mean a total change of name, or just a slight mistake?
I understand you mean a completely different name - in which case I cant understand why you are surprised that BA (or any other airline) would make a charge - they would treat it as a different traveller.
The whole reason that name changes were "banned" (Travel agents used to be able to change names without any problems up until approx 2002) is because "some" agents used to book the very cheap advance tickets for peak travel dates, wait till flight sold out, and then sold them on with huge mark ups - just change the name.
I think any airline would take a lot of convincing that a ticket booked in the name of Ms Jane Smith should have actually been booked for a Mstr Seven Cooper (or whatever).