DSV lost my degree

DSV were supposed to deliver my UNISA degree. I received a call from them on the 28th of December which I missed as I was away. They called me again on the 4th of January to say that they will deliver within the next day. I received another call on the 6th stating that they would deliver by the next day. I waited at home and no one came. Since then, my parcel has not been scanned by them. It has been over 3 weeks now. When I call and email, all they say is that they are 'investigating'. They promise to get back to me but never do. I have sent numerous emails asking how long their investigation will take and received no response. They have said that they cannot locate my parcel, but they are yet to classify it as 'lost'. This is an incredibly important document which they have lost and UNISA do not reprint degrees.