New intermittant faulty phone scratched by Techs

Purchased NEW contract+NEW Grand Neo Plus. With many extras.Within a week on 1 occasion my phone would not turn on. I had to remove the battery, re-insert and then it turned on. On day 8 this occurred again. Witnessed by Vodacom employee. She stated that it was out of 7 days and they could nothing. Next day my phone kept display, \Not registered to Network"I went back to store and that tried to fix. They did a SIM swap and asked me to wait 2.5 hours and then turn it on and should be fine. I did and it was not fine. The same problem was there. I phoned them and explained the situation. They said to come in the next day with everything and they would book it in under OBF (Out-Of-Box-Failure). I wrote on the form that it will Not register to network and intermittent power on problem. Phone was handed in on 5th June. 17th June I was told it is back at the store and that they found nothing wrong. 18th June at midday I went to collect my phone and found that the case had scratched on 3 separate sides. I have refused to accept the phone as it has been damaged by a negligent Technician.I wish for Vodacom to cancel the phone and refund me in full and I can choose a new phone. """