Worst customer service

Totally dissatisfied with the lack of effort shoprite put in trying to resolve my query. I bought a few items from shoprite this past Saturday and one of the items was scanned twice meaning I paid for it twice and didn't notice at the time. When I tried to get a refund for the item that I was charged double for, they said footage only lasts for 24hours then it's gone and they can't assist me with this, even when the slip showed my name on it as I also swiped my x-tra savings card!!!