Damaged brand new upgraded phone not replaced

On 20/07/2015 My new I phone 5 was delivered by vodacom and on 21/07/2015 I did a simswop. When my simswop was completed and the new sim activated I found that the phone that Vodacom has send me is faulty. I phoned the call centre on 22/07/2015 and they said they will replace my phone(ref S3-8d281-16 NN). A courier will pick it up and bring me a new phone. After 2 weeks vodacom still have not replaced or picked up my phone.On 3 August 2015 my wife and I phoned vodacom again and got a ref number UR844666. they informed us they have no stock and will send it as soon as they have stock. On 12 August 2015 my wife phoned vodacom yet again and spoke to a consultant for almost an hour then they said we will have to Wait indefinitely due to the fact that they have no stock. Why do I have to pay for a contract and phone but the phone they send me is faulty. Why do their consultants send us running around and not help us. It has been 2 months since we received the faulty phone and we have no positive response from vodacom at all.