Swapping: A new one or refurbished?

Hi guys,

As many of us are here complanining about, I have been having the networks issues with my iPhone 4S.

Then, I pay a visit to Apple store and swapped my phone. The new one caused the same problems after some time, therefore, I swapped my phone again for the second time.

At my first swap (1 week after my purchase) they gave me a brand new one from the original box. However, at my second swap(3 weeks after my frist swap), the Genius guy brought a phone in a black box. I persisted to ask if it's a new one or a refurbished phone. He claimed that it's totally a new one.

However, I am still not sure about this. This will not change anything but I just wanted to know if Apple provides additional brand new phones for swapping in a different box, or do they prepare refurbished phones for swapping?

I would appreciate if anyone knows Apple's approach for sure.

Cheers.