Mr price home gift card redeemed by someone else while we still in possession of the card

<p>Returned an item on 17th July 2016 and received a gift card with a "suppose" credit on the gift card. When we tried to redeem the gift card today at gateway mr price sport we were told that the card had a nil balance. Cashier advised that we go to argyle road to sort out. Drove all the way from gateway to argyle road only to be told that the gift card was redeemed on the 20th July 2016. Adamant that we did not redeem the gift card. A different person had redeemed the gift card that we were in position of. Please explain to me how this was possible. All the assistant manager could tell me after more than half an hour was that there's nothing he could do but will investigate and let us know. What was there to investigate when he had proof someone else redeemed the card. Because of mr price incompetency I had no gift card and wasted my petrol and waited so long only to get no solid answers. They called the person who redeemed the card who confirmed that they didn't even know who we were. ****************.</p>