PARCEL OPENED GOODS MISSING

on the 12 / 08 /2015 i assigned courierit to pick up a parcel from johannesburg to durban next day service.the next day i never receive the parcel when i called in to track it they tell that they can not seem to locate it and that they will call me when they find it.1 hour later they call to tell me that they found the parcel on the airport and it was opened and stuff ****** (to the value of R5750) .Courierit says that they used bidvest to airfreight my parcel and that bidvest is too blame and i need to claim from bidvest as their staff committed theft .courierit does not want to take responsibility for this as i sign my contract with courierit .