Lock Button Broken, Apple Store

Hey guys, i have an iPhone 4 and was always in great condition. ive had it for about 5 months now and always kept it nice. there are no scratches other than some on the edges and what not, but other than that, still looks good. but recently my lock button broke... it went from working perfectly to getting stuck in a matter of seconds. Tried everything but the thing is just stuck. i went to the apple store (i was luckily in the mall when it happened) and they told me to schedule an appointment with a worker and i may be able to get a free exchange if my phone meets the requirements. i made the appointment which is in a couple of days, but what im wondering is do you think ill get the free exchange? i have 1 year warrentee and no water damage. just a stuck ass lock button lol. what do yall think? thank you for any feedback