Backpack ****** at check in counter

My brother was travelling on the 18:25 flight from Johannesburg to Durban on the 3rd of June 2015. He was checking in and was placing his bag on the scale. While his back was turned someone removed his backpack from the trolley. He left the counter and realised it was missing. When he returned to ask them if they saw it one of the ladies at the counter refused to help him saying she did not serve him. Pathetic service as usual from mango. Have been trying to call them from last night and no person seems to be able to help. We cant even view the footage to check what happened. Will never use them again.