Thanks for your support all, I'm in a much better frame of mind today...
Just for interests sake.
The money was withdrawn by some UK company? Not sure who, but there was three withdrawels, all incurring a overseas transaction fee.
The bank this morning said it was definatley fraudulent and they would begin investigations.
They also advised me that if it was not resolved within 7 days, they would provide an account on which I can over-draw the savings account in question until it is resolved. That's helpful atleast.
Thanks again guys.