Iphone 5 lock/ off button not working

I bought it 6 months ago and the on/off/lock button hasn't been working first i had to press it two times then i had to press to the left and after i had to press it to the left and a couple times and now its just not working anymore i have at&t and i don't know if they'll replace it because it has some scratches on the back (above where it says iphone & on the apple logo on back) but they are (minor small little) not huge and if they do replace it would it be with a refurbished or new one? And what does apple do in these circumstances i heard the phone has one year warranty from both at&t and apple please help me

Doesn't hurt to take it to an apple store or AT&T store. Does more than asking on here.

Well, do you have a case on it? That might be the problem. And AT&T would most likely give you a refurbished one that costs around $100. If you go to apple they MIGHT give you a brand new phone for free or little charge, of that's your first time. And if you don't want to do any of that you can go to setting general and then accessibility, and you can turn on assitive touch which is like a clickable button that you can out in your screen and when you tap it you can go home, lock screen, rotate screen, change the volume, lock screen, unlock rotation, screenshot, triple click, multitasking and shake… Hope this helps.