IPhone 5S wont turn on after update?!

I updated my phone to 7.0.5 and now it wont turn back on, I don't know what to try and I've only had the phone for like two months!

Please help me:(

Try to hold down the power and home button to see if it restarts. If not, try the same while it's connected to iTunes.

I'd recommend exactly what the other user has said but I'd like to add something. If it still doesn't work I highly recommend contacting apple. I recently had problems with my iphone 5c and I went onto the apple website and was able to live chat a member of staff. They are really helpful