Quote for a phone under warranty

I took in my phone to Vodacom Centurion branch as the screen of my IPhone 6S never responds, and I constantly need to reboot the phone. The lady there told me that there are no IPhone parts and the phone would be replaced, but now if I track the job ********** 2 I see that its logged under 'Non warranty' The call centre agent tells me that this is because the phone has scratches on the back cover and on the sides (how does relate to the screen not responding) And apparent scratches on the screen (I have had a screen protector which was only removed last week because it was old ) To void warranty just so you can ******* your customers is shameful !!!