iPhone 5 question

Since the iPhone 5c replaced the iPhone 5 what happens if my sleep/wake button stops working and it needs to be replaced? Do they give me an iphone 5c or 5s? I ask this because this happened to my 4s and they just gave me a new one? But now they are no longer producing 5's .......

I would love if they gave me a 5s .....but they would probably give me a 5c !