Still waiting for my iphone

I upgraded my contract online and ordered a white iphone 6. A few days after a black iphone 6 was delivered. After complaining on Hello Peter Vodacom agreed to exchange it and about 10 days later delivered a white and gold phone. The phone however was damaged and they came to collect it a few days later ( on or about 1 April). I am still waiting for my third phone to be delivered and was told this morning after leaving unreturned messages for Zanele that there is no stock according to the system but she knows that there are 5000 phones in stock. She said her colleague is investigating this and she will call me back. It is now 17H35 and despite one more unreturned message I still have not heard from her. I am beyond frustrated and now considering cancelling my contract.