SAA Staff cut lock and ripped zip off the bag, and they will not pay for the replacement of the bag

My husband recently returned home after two months abroad for work, when he arrived in Durban, luggage handlers had cut off the lock on his bag, and ripped the entire zip off the bag, in an effort to get into the bag and ***** items. This was immediately reported to staff at the airport, and he was given an email address to email. We have spent months going back and forwards with them in an attempt to get the cost of this very expensive bag paid out to purchase a new one. We eventually received a payment of R500 (the bag costs appr R10 000) this was after 3 months of emailing with constantly not response, and after sending proof of cost of the bag, as well as photos of where the zip had been completely **********. They are saying that they do not cover "zip damages, or any part that protrudes from the bag" Photo proof was sent to show that the zip on this bag does not protrude, it has a heavy duty fabric flap that runs around the en tire zip, to protect it. Further to all of this, it is clear by the lock being cut off and the zip being ********** that this is not simple damage, it is the direct result of someone breaking into the bag with the in8tent to *****. SAA needs to take accountability for this, and refund the bag.