Boom gates close on cars!

On Saturday, 1 August 2015 at approximately 17:40 my wife and I was on our way out of the Rosebank Mall. It was busy so we were told to leave on Craddock Avenue. Upon waiting for ages, we finally put our ticket in the boom and drove to leave. The boom, to our shock and horror, then closed on the car (Orange Ford Ecosport). What is concerning is that there was no guard or staff to help us assess the damage, as well as the sensor on the boom not working. This is unacceptable. What type of Mall allows boom gates to close on cars? We were incredibly shocked by the occurrence. We often frequent Rosebank and do know construction is taking place