Water in Diesel

My wife filled diesel on 12/07/2023 at Elegant Fuel, Marshallstreet, Polokwane. The vehicle was almost empty before she filled and after filling diesel she experience problems with the vehicle where an fuel warning light came on indicating water in the fuel. I contact the filling station and spoke to Mr Kobus and explained to him. He said that he will revert. The following day I went to the dealer where they found water in the filter water trap. They cleaned an replace the filter which cost me R 1166.82. I called mrs Zilla Ferns***ner) at the filling station as mr Kubus never revert to me. I explained to her where she said she will investigate. She called me and told me that they conducted a water test on their diesel tanks and no water was found. This was a day after the incident. She then said to me that the origin of the problem is not from them and they will not be liable for it. This is still a new vehicle and didn't have any problem until diesel was filled at the above mentioned filling station. We can't use the vehicle currently as it need to go back to the dealership for cleaning of the tank, flushing of the fuel pipeline and replacement of the fuel filter. I will never fill up again at this filling station or refer anyone to this filling station.