Poor service received

Yesterday received the worst service ever. Staff needs training. I bought items and transactions went through, but receipt didn't come out. Money went through. Showed them on my app , confirmed. Waiting over an hour in the shop. Receipt never happened yet they took my money. I asked them to either return the money or give the purchased item . They refused. Im very disappointed in the service. If they have any technical issues how is that my fault. Why hold my money hostage?