Whats wrong with my iPhone 5s? (touch screen issues)

So on New Years Eve, I bought the iPhone 5s. (like 3 weeks ago...) and just since yesterday, everything has been going wrong with it. things first went bad when I was charging it and I went to sit down on my couch and it shocked it and since then, when it's charging the screen is very unresponsive. I tried restoring the software on it and that didnt seem to help. Also, the lock button on the top rattles. I have seen people posting about that and say that Apple refuses to repace it for that problem. If I bring it to the Apple tore will they replace it for free? I think when it shocked it that is what screwed it up with the touch screen. I do have applecare but want it replaced for free and not have to pay the $79. Thanks