Destroyed suitcase and luggage due to company negligence

Worst experience ever! During my trip from Stellenbosch to the Eastern Cape, the compartment that luggage is stored in opened in the middle of the road. This was because of negligence on the company drivers side because they didn’t make sure the compartment was closed properly. My suitcase fell out into the road and broke completely. I also had damaged luggage items due to this. The customer service people refuse to take responsibility for this negligence. They told me to make an affidavit of the items missing and when I did that, they asked for receipts of all the missing items, items I had bought ages ago. Customer service then told me that they were only willing to pay for the broken suitcase and not the items that were ruined because of their negligence .They refuse to take responsibility for their negligence and keep giving me the runaround.