BA to pay for the time you have used on the shopping spree? It seems that you have been reimbursed for all expenses despite that £700 is quite a high amount, and in addition to that BA has thrown in a £250 credit. What more do you expect? BAH is not going to refund parts of the costs of the trip; there is no basis for demanding this.

It seems that you have received more than you are entitled to under law,