paying for a phone is don't have

first i booked in my phone for repairs in October 2015, the screen was broken and sensor was not working, i specifically stated that. the phone took longer than the waiting time for me to get it. when i finally got on the 15 december 2015, i only had the phone for a day, when i stated using the phone(used it later because the consultant who assisted me never told me to remove my sim card and memory stick,they lost my stuff,i paid for the sim swap and bought a new md card) i realized the sensor still does not work. i went back again to vodacom westgate on the 22 december 2015 to tell them the issue, they said it needs to be booked in again. now they expect me to pay another access amount required for something i told them to fix in the 1st place. now i called the call centre to check the phone is, i was told the back screen is cracked, so i need to accept the quation and pay what needs to be paid. the phone was fine when we booked it in, it was only the sensor. I DONT WANT THAT PHONE ANYMORE!!!! VODACOM BETTER GIVE ME A NEW PHONE!!! THEY MESSED UP THE PHONE AND NOW THEY EXPECT ME TO PAY FOR IT? NO WAY.