Trolley Collectors block car

On 26 February at Forest Hill City I had the worst experience ever with the people who collect trolleys for Pick n Pay. I got an open parking spot which was next to some trolleys that was already standing there. I went in to Pick n Pay just to get something I was inside for about 10min. When I got back to my car the trolley guys decided to pack the trolleys around my car and lock with a cable through all the trolleys and around the pillar. Meaning I could not move the trolleys and I could not get my car out. I went to Pick n Pay to find out *** is going on as this is a normal parking bay with no signage or anything to say it is meant for trolleys. A lady by the name Elizabeth assisted me and tried to find the trolley guys. After about 30min the guys returned only to argue with me saying the parking bay is for trolleys. Well there is no signage saying it is for trolleys. Elizabeth told them as well that they are wrong for doing what they did. But they still argued saying I was wrong. I feel very upset with Pick n Pay as it is their trolley guys what if they damaged my car what then. Thanks to Elizabeth for helping me. Pick n Pay will not see me again.