Why won't my phone power up?!

I was pretty stoked with this phone when I got it 4 months ago and it's fantastic. The other day I put it in my pocket and noticed it was turned off. Now it doesn't even power on. It doesn't show the battery charging icon no matter what I do, I even tried the official troubleshooting guide online. Nothing, nada, zip! The only thing that I can guess that might have caused this that the cheap case I bought for it started breaking apart on the side where the button is. Phone would slide in the case turning it off which I would realise when I took it out of my pocket to turn it back on. This time it won't turn on at all!!