no gift vouchers after 4pm

this afternoon around 5pm I went to Checkers in Norkem mall, Kempton park to purchase gift vouchers worth R1500. I was told only vouchers worth R300 were left and the lady/ladies that had the new voucher books had left work at 4pm and locked the books in their office. The supervisor was called and she told me the same story. So I questioned their service as to whether anyone else has access to the so called office and could possibly retrieve the books so that I could be serviced. The response was no. This is very shocking to me as a customer that if a certain person is gone home with the office keys then certain services cannot be rendered yet the shop itself closes at 7pm. Highly unacceptable and they have lost me as a customer. The supervisor seemed to have no clue of customer service and saw nothing wrong with this poor operational issue from this store. its little things that chase away customers. very unhappy.