Believe it or not, the usual complaint we have in this forum is that BA is too slow to collect credit card payments (and dare I suggest, occasionally forgets to do so), so if there is a duplicate charge it certainly isn't organised. On the other hand BA's IT is a frequent area of complaint here and so it wouldn't surprise me if there was a duplicate charge due to some refresh going on. In about 35 years of transactions with BA I think I can recall one such incident and that was automatically credited back. If there is a booking set up, by all means get BA's Contact Centre to reverse the booking. If you prefer you can use Twitter and get into a Direct Message exchange with an agent. If it is a simple duplicate then your credit card issuer should help you resolve this, since frankly it is a fact of life with online transactions. If you are 101% sure it's fraudulent then by all means talk to the police in your jurisdiction but I would be very surprised that anything come of it. By issuing 125 tickets BA is then obliged to account for the transaction and they don't want a mess in this area any more than you do.

In your first day on FT you are restricted to 5 posts on your first day, this is to stop our own problem with online transactions, but after 24 hours you will be able to post again.