Petrl tank left open by petrol attendant

I went to BP Malibongwe to fill my tank yesterday. The service attendant was friendly and helpful. The next morning I got a pic from one of the residents in my complex that my petrol tank lid and cap was open. It was getting dark when I got home so I didn't notice. I quickly went out and closed it. Thankfully I had parked under a carport that prevented the sun from getting through. Petrol is highly explosive. To think there are kids in the conplex, pets, people that walk around. Had there been an explosion, it could have been so awful. I called them. The guy who assisted me answered. He said he was the manager and that he closed the lid. I told him to check the cameras and come back to me. That I wanted to speak to his boss. That I'm not sure if he petrol dried up, if my tank is a little heated from the weather, if it's safe to start my car as I needed to go out. The same guy called me back a short while later. He apologized and that my car was safe and said that his boss would give me a R200 free fill and a cup of coffee. Obviously the camera said otherwise. I explained the seriousness of this and it should never happen. I am scared to start my car. R200 and a cup off coffee wouldn't make it ok that a disaster could have happened which could have killed people. It could still happen. I am terrified to start up my car.