parking traffic cause me over time, service not satisfied

yesterday, i went to Dischem centurion mall to buy medicine. i paid my parking ticket according to the machine shows R10, then i immediately went to my car and drive off. but in the parking, there is huge traffic jam, when finally my turn to go, seems like i arrived at the boom gate later than 15 mins, so the the boom gate doesn't want to open, then i pressed the button to speak to the service. the lady who spoke to me was very rude, she insist on letting me to go back and pay for extra, which is impossible, as it was also not my fault to cause over time. there was a security guard standing at the boom gate helping customers, he even talked for us, as he can see what is really happenning at the parking and how bad was the jam, maybe that's the reason causing the jam, as everyone had to call for service. centurion mall really need to inmprove on their service.