Repairs of Iphone 6s

I took in my iphone 6s for repairs as the rear camera was not working. They told me that I will get my phone back within 7 - 14 days. On Saturday around 16:00 they phoned me telling me that they will have to replace the phone as they cannot fix it. I was informed that I need to pay R5000 for the replacement. Why should I pay R5000 if they cannot fix my camera. The phone is irreparable and I must pay in the money. Why should I pay 5000 if Vodacom cannot fix the camera. I want my phone fixed as it is still under warranty. I have done some research on the internet and most people had problems with their camera and their phones were fixed or replaced, so why should I be pay. I cant be ********** by Vodacom. I got the most expensive phone and now the phone is faulty and Vodacom is now shifting the blame to me. I want my phone working properly that's it and I am not willing to pay anything. I brought in my phone for camera repairs and I am expecting to get a phone back with a camera that is working properly. I have been without a phone for a couple of days worse off I couldn't even get a loan phone from Vodacom.. what kind of customer service is this