Problem with manager

I visited Mr. price sport in Rosebank yesterday and tried on some clothes. I unknowingly left my car keys in the fitting rooms. By the time I discovered they were missing, Mr Price Sport had closed. I went immediately to mall security, who informed me that items left in store must be delivered to mall security at the end of the working day. A call was made to MRP management who confirmed that I had left the keys in store but they couldn't open for me until the next day. Unless, I was willing to wait several hours and pay the managers transport costs. This is seriously unprofessional. My complaint is not that they refused to return to open the store- I can understand this. My complaint is that staff didn't act according to procedure and didn't have the foresight to understand that if someone leaves their car keys in a shop, they cannot go anywhere. The keys should not have been left in a locked shop. This has caused huge inconvenience and expense on my part, as I am not from the area and had to find local accommodation for the night so I could come back in the morning to fetch my keys from the sheepish staff who claimed they were still new to the job and didn't know what to do.