Cellphone Screen Cracked by Vodacom

On the 02/04/2015 I handed in my I Phone 6 which was purchased on 18/12/2014 for a repair under warranty as the speaker was not working and I could barely hear on the phone. I also asked for an upgrade on software and to check why the phone was freezing from time to time. It was handed in to an efficient salesperson Shaun who said it would be sent for checking. He fully inspected the phone and gave a report of no external damage on receipt number ***6. A couple of days later I received an sms indicating a charge of AROUND R4000-00 plus minus for repair of cracked screen. I sent many email and to Vodacom headoffice and the branch in Vereeneging to query this. Eventually the phone was sent back to Brooklyn and my driver collected it and it had a broken screen. The workshop indicated received broken and the store sent in good order. The courier must have broken it. I am extremely unhappy as no one has taken responsibility nor fixed my phone. I have all documentation