Worst Treatment by Shell SA

I went to Shell Ultra City Polokwane N1 South and I asked that the attended fills up my vehicle's tank with petrol, to which the attended filled up the tank with Diesel. The car drove for some kilometres and started giving problems. I returned back to shell and they acknowledged that there was a mistake and tried a quick fix method which even got me into further troubles. After the quick fix by what would seem like a bush mechanic that was arranged by Shell, my car drove for further 80 KM and damaged there whole engine even knocking holes it the block. Shell refuses to pay for the damage, which doesn't make sense as the vehicle was driving well before I went to the garage. To add more salt to the wound, shell asked that I tow my car to Hyndai Dealership where they authorised that my vehicle get stripped for inspection of damage. Hyndai stipped the vehicle, Shell is refusing to pay for the repairs and Hyndai refuses to release the vehicle back to me because Shell refuses to pay for the stripping and storage costs at Hyndai. I'm lost for words with the sheer arrogance and disregard for the next person that has been shown to me by Shell