The incident took place at about 7.40pm last Thursday.
According to police spokesman, Capt Johannes Ramphora, while the manager was working, he saw a group of about 15 armed suspects enter.
One of the men shot the security guard in his left leg and took his pistol.
Three others escorted the the manager to an office where they took an undisclosed amount of money.
The group then fled the scene in a kombi.
No arrests have been made, but a case of business robbery is being investigated.
