Petrol in diesel vehicle. Franchise owner throws phone in client's ear

I stopped at the garage and asked petrol addendant to pour R1000 diesel. As he started pouring i saw he is standing looking nervous. I asked him if he is throwing diesel. He then said he made a mistake he threw petrol. I asked him how many litres he threw in and he said 4 litre. On my tank on the inside is also a large sticker "diesel". They said to me because it is only 4 litres it wont matter if we fill up. I then phoned Renault after hours support and told them what happened. They informed me that Renault will dispatch a tow teuck in circumstances like this but the owner of the petrol station must take responsibility and pay for the towing because it will not be covered under guarentee. I then phoned the owner Mrs Van Der Walt and told her what happened. Before i could continue she was very rude and told me she does not take responsibility for what her petrol attendants do and that it is my responsibility to check. I informed her that as business owner that is what Business insurance is for and that i take responsibility for my personnel if they cause damage to a client in my premises. She threw the phone down in my ear. I am shocked that a franchise owner of such a large Franchise can act so rude and sureley against Franchise policies and procedures.