Bad service.

Purchased a gift for a friend for R220.00 on 28/03/2018 for her birthday. Saw my bank account statement and it showed the amount was debited twice. I approached the store and the lady told me that as it was a weekend it will probably reverse by Wednesday and if not then I have to bring in a statement to show and they will take it up with their finance department. I was shocked. What if the purchase was R5,000.00? . She says there is nothing can do as it is a "wait and see" scenario. This is unacceptable as the error was not mine yet I may have to pay for a bank statement to prove I was debited twice despite showing them the transaction reflecting twice on my cellphone banking. I will never shop there again. Cash is definately not king.