Broke the air-lock due to their mistake

My kids and their cousins asked for 16rand petrol (1 liter), attendee threw in 60rand petrol. Elvina advises him to extract it from the car as if it were the kid's fault. At this point my son tells them its an air-lock tank which makes it extremely sensitive. After keeping my kids waiting for 30 minutes, they used a freshly-cut pipe along with a metal rod used for pumping the wheels, to extract 1lite of petrol. Which they struggled to extract due to the tank being air-locked. AND then this same attendee invites my son to a fight, after putting them through such a humiliating ordeal. When i spoke to Elvina, she has the nerve to tell me she does not know who was at fault.