attacked by store security

I was attacked by the security guard because I entered the store with a plastic bag containing shoes, when I tried to explain that the plastic contains items not sold in the store and that I would not object to them examining the contents when I leave the store the security guard did not listen but instead grabbed the plastic containing shoes and threw it where the put their trash. He damaged the bag during this process. When I tried to retrieve it he threatened me and at stage I was traumatised by the event and feared that the attack would turn physical. The store manager did nothing to reassure that the incident will not happen again and that corrective measure will be done. After the attack I informed by some of the customers that it is not the first time something like this happens by the same guard