I'm going to the Apple store to fix a button. Will they fix it or replace it?

Also will they fix it there and then? It is the volume down button on my iPhone that is broken. Also if they replace do you think they will let me switch to a white iPhone 5 from a black one?

Thanks in advance.

Added (1). To the first answer. How is getting a replaced iPhone 5 that is a different colour like swapping a broke XBOX 360 for an XBOX ONE. It's completely different. I asked for an iPhone 5s then yes obviously they wouldn't but a replacement of the same phone but in a different colour? I'm sure they would… Why not.

It Depends. If It's Not Working Its Maybe A Bit Of Dust But If It's Broken Its Not Working And They Will Replace It And I Don't Think They Will Swap The Phone It's A Bit Like Breaking Your Xbox 360 And Saying Can I Have An Xbox One Insted.

Depends what is wrong, they will know when they look at it.