Hey,
It sucks your s4 stopped working. I've had that happened to me twice. They are really good soundwise but quality isn't so good.
You should be eligible for a replacement if you bought them from a legit seller. You only need to send the head phones back(without the silicon buds). As of what they'll send back, ymmb. The first time I claimed warranty, they sent me new headphones. The second time, I was sent an unopened new retail box.
Goodluck.