paid but I wasn't allowed to take what i've paid for

I went there on 20/09/2015 @09:00 to buy toilewusing a gift card. after swiping the card the shop was hit by loadshedding then the power came back, the receipt came back saying retry the transaction when the cashier swiped the card it declined cause the money has already Been taken on the first transaction. the casheir called the manager which she asked me to leave the staff behide which I paid for and I had to come back today. she didn't apologies for the matter nor explaining what will be done I sat in their office for 30minites one of the staff came in and checked the card# and she saw that the mom net went through. I had to sign some papers saying they paying my money back while they asked it back and gave me the toiletries which they refused to give me yesterday. the manager didn't apologies for the inconvinients I wasn't treated has a valued customer and I don't want their apology. and they all have attitude including their managers