Intercape Refusing to compensate me for my lost bag due to their negligence

Im sooo hurt by Intercape. I boarded a bus from johannesburg to Cape Town on 7th April when I got there my bag was missing. The drivers told us that our bags were stollen in Potchefstroom by some ******* who noticed that the trailer was not locked. The ******* apparently grabbed a few bags and ran with them. Intercape told us to go to police station do affidavit of everything in the bags and only to tell me that I was supposed to insure my bag they won't be compensating me for my ****** clothes and the bag. This was purely negligence from their side it's not an accident for them to tell me about insurance it's negligence it's like they gave my bag away. When I asked why the trailer was not locked was told the drivers only had one padlock and they used it on the side of the trailer they only removed the padlock from the side to the back after the incident. Why it was not locked in the first place, why they had one padlock instead of two. I'm not accepting this and will do everything and anything I can to get compensated for my belongings if it means I must go the to tribunal and ombudsman I will. Intercape I want my compensation for my loss. I had new clothes, shoes, perfume, and etc there which are not cheap. I paid alot of money for those things, for Intercape to tell me I should have insured them.