IPhone not being replaced - under warranty.

I received an iPhone from Vodacom five months ago. After not even three weeks of having the phone the battery started giving me massive issues. I took the phone to Vodacom in JHB, who told me to take it back to the store in Durban (please request footage - Vodacom Nicolway). As I do not live in Durban, I was unable to take the phone their earlier.

In the mean time, the phone screen cracked - the Vodacom technician confirmed that the screen cracked due to the faulty IPhone (battery bulging due to fault). The iPhone's battery was so obviously faulty from the get go.

Instead of the phone being repaired or replaced, Vodacom is refusing to assist. How is it possible that a iPhone which is not even 3 weeks old is so faulty that it is not working anymore and the iPhone is not being replaced or repaired. This phone was (and is) so obviously still under warranty.

How is it possible that a 3 week iPhone is so faulty and is not being replaced. This is utterly unacceptable.