Items scanned twice

Purchased groceries on Saturday afternoon and left the store just after the 5pm closing time. I had to tell the cashier that some items that were scanned were actually reduced. When I got to my car I checked my receipt and found that there were two items being the Toilet cleaner @ R15.99 and Chilli Bite mix @R10.99 that were scanned twice. I approached the security official named Innocent and he refused to allow me back into the mall as it was closed and referred me to the staff entrance. I also tried to call the store but there was understandably no answer since the store closed at 5pm.<br> I am now sitting with a receipt for items which I was charged for but do not have. Please advice on how I can get my money back.<br>