After having secured the safe return of my £3,800 of hard earned cash, I've now started to take on the Halifax over my credit card.
Sent off a S.A.R - (Subject Access Request) on 27th Feb 07 via Recorded Delivery, and received a very confusing response today which said, "We've answered this already.............here' s a copy of the letter................... .." and it related to my current account S.A.R - (Subject Access Request) from back in October

(And to think I used to trust them with my banking).
Having checked back over my Subject Access Request, I state quite clearly that it relates to my Visa card and quote the visa card number on it too.
All barring a miracle, I don't think I'm going to get a response within the timeframe for the visa Subject Access Request.
Let's see what next week brings!