damaged my goods at store

Vodacom for over 5 years and I have never had such bad level of service like I have had since I handed in my faulty devices on Tuesday 9 June 2015 at N1 City in the Western Cape, first my device had no scratches on it when I gave it in to the manager on that site that said I would get a call in the week to know what is happening sadly to say I got no call, went to the store today 13 June 2015 and they told me my device will not be changed as there is damaged on it, there was a long scratch down the middle of my device that was never there and the device was only two days old so I ask what's is going to happen now, manager Michelle state I must raise it with Sony, I said that's not right as she did the booking in of the device and it had no marks on it, then change her story and stated she would escalate the matter on Monday. it is not my fault the faulty devices got damage in Vodacom care that is only 3 days old. Further more I was told I don't get a copy of the booking of the device beeping faulty, then tried to say it is also because of water damage, but the device is water proof. and I've now been waiting 3 weeks for a reply and nothing. I have to run around for answers.