Lack Of Liability for Item Damaged in my Premises

Whilst delivering other items to my business the team were warned to be careful. Under supervision of highly untrained supervisor - Raymond - the team bashed into a 1930'3 rare plinth and smashed it. The supervisor was un-trained . We are not cover for work man breakage only for client breakage . Stuttaford Van lines sent someone immediately to take pictures a few days letter still no sense of responsibility . After a few calls and emails i got an email from Mel Potgieter the Branch Manager saying : "who have already advised that we have a limited liability of R600 per cubic meter of household goods carried by us only and that this item would not fall within this limited cover". This indicates that they are trying to claim under the goods that were sent to me form Cape Town and not the item which was damaged which was in the shop. The fact they took a few days to come back to me on this and did not have an immediate answer as to what their responsibility is - is shocking. Surely South Africa's top art and antique moving company should have better staff than this and better back up for the clients.