Terrible manager

I was at Shell garage in Alberton where I asked the attendant to fill me up with unleaded 95. He put the pump in the tank and went off to wash the window. I'm not certain if there is something he was supposed to do that he didn't but the pump didn't kick out and the fuel spilled to the ground and the attendant was notified by another client who was driving past and noticed the spilling of fuel. I still had about 72km left on my fuel which is about 5L if I'm not mistaken. I requested the attendant to call the manager as I wasn't going to pay R831.60 for that fuel that was on the ground. Riaan (the manager) came, the attendant explained what happened then Riaan tells me that the best he can do is 2L off so I asked him how it's my fault that their machine is faulty or his staff isn't correctly trained and why he makes it seem as if he is doing me a favor. Mind you even if my vehicle is on reserve I don't pour that much fuel. I informed him that I fill up there often and swipe my card there and if they have back-up or something where we can check my pattern. This guy looked at me and ask me how on earth he's supposed to keep information of all his clients. He later turned to the attendant, screamed at him and to him that he would pay for it if I don't. So I told the guy to bring the machine and that I would pay for it. This manager said, "I tried to help you ma'am but you are not allowing me so yes, pay the full price!" I paid and I left. My entire car smells like fuel and I spent over R800 on fuel that was also on their ground and on my tyre. I am truly upset and disgusted by how this man treated me and how he did not even resolve this issue but made everything seem like it's my fault.