iOS7 iPhone

I have an iPhone 5 and I recently updated my system to iOS7; The upgrade went worng and now my phone is not working.
I went to a MAC store where they told me my one year guarantee had already expired (a week before) and that there was nothing they could do about it.
I found this answer unacceptable as it was due to the upgrade that my phone is no longer working, I had no issues before the update!! It was not my fault the iPhone is not longer responding (I didnt do anything that could have damaged the equipment ... except for the update....)
I have been buying iPhone's (since they first came out), and I also have iPods and Macbooks, I found this attention really disappointing and I'll be thinking it more than twice before buying any other Mac product from now on.

Is there something I can do to have my phone working again?

Thank you..