What would you be?

We went food shopping this morning to Sainsbury's, as I had a £12 off a £60 shop.  So far so good, but when we got to the checkout, the till wouldn't accept the voucher. The assistant called for a supervisor, but no one came. A queue was starting to form  so she said I would have to take my till receipt  and voucher and go to customer services.   I  explained what the assistant had told me, and she said, I can't do that here. As luck would have it, another assistant appeared, obviously more senior, and said the only thing they could do was give me a £12 gift voucher, or refund all my shopping and put it through the till again.  I wasn't very happy with either option, but as the gift card is valid for two years, and can be spent on food, I reluctantly agreed  to the voucher.   It's World Book day on March 2nd, maybe I should dress up:-)