Safair

Took a flight from jhb to Durban on the 26.08.2022. Checked in my luggage at jhb 19kg. Got to Durban my luggage was opened and was 15.8kg. Laid a complaint and open a file. Safair doesn't was to take any accountability for my loss and is only willing to compensate me R500. Worse airline ever please advise on the legal steps i can take