Damage to Vehicle and refusing to pay...

Good-day<br> <br> On the 21st of January 2015, I went as normal to our petrol station around the corner from my house to put in some petrol and had my oil and water checked. After the attendant was done I paid for the petrol and left to see my 1st client in Cape town, CBD. Hitting the morning traffic into town, I noticed the car starting to over heating, however because it has never happened before I just assumed that the fan would switch on but didn't. After, I got in to town and saw my client as I was running late I found that my water cap wasn't closed properly. Now, to cut a very long story short I went back to the service station where I filled up for petrol that morning I first addressed attendant that assisted me that morning and he denies even working that. Then I met up with the owner Mario, that knows me and my brother as we normally fill up at his station and have been for the past 5yrs. He told me to get a quotation of the damages so that should they find the attendant guilty they would pay for the damages but have now refused to do so. I have also reported this matter to Total Head Office, but until now nothing has been done.