My volume rocker is uneven?

I received my T-Mobile iPhone finally, gold 32gb after about a month and a half of waiting. But when I received it, I noticed the volume rocker was uneven. The down button is a lot more recessed, and almost flush with the phone, while the top button is normal i think? My friends iPhone 5 buttons are both even and click very nicely. My iPhone 4's buttons are also even and click very nicely... But with my 5s buttons, the down one is really hard to click while the up button is very easy to click. With my case on, if I slightly put pressure on the lip of the case, the up button clicks by itself.

Is there anything I can do or is this not covered by the warranty. I haven't dropped my phone and only had it for 3 days.