Can I get a new Iphone for the same carrier? (I'm still on my 1-year warranty)?

So I've been having problems with my iPhone 4S speaker it's been 2 two times I had to go to apple and get it fixed but it just keeps getting blown I'm starting to think its a malfunction or a defected problem an apple employee told me that if this happens again that they would have to give me a new iphone and I want to get a new iphone but can they put the carrier info. On to the new iphone, my carrier by the way is virgin moblie and I just know that the carriers they have in Their store is AT&T and sprint and verizon? Does anyone know if they can keep my carrier on the new iphone?

If it's defective and still under warranty - yes.

Talk to them for details.