iPhone damaged by overheated battery?

So I use an otterbox case on my iPhone 5. I'll admit that I drop it occasionally, but that's why I have the case, right?

Anyways, I took off the case the other day and noticed that the metal backing to the phone was completely bent backwards. probably 3-4 degrees away from the glass screen. I left the case off for the next day or two and noticed that when using the phone the battery gets extremely hot during use and while charging and that the metal backing becomes much flimsier when that happens. I haven't gotten any temperature warning but I'm sure this kind of behavior with the phone isn't normal.

The right hand side of the screen is starting to develop cracks underneath the glass because when I press on the top right corner of the screen it bends backwards to meet with the aluminum housing. I'm concerned that it may damage the touch receptors in the phone and it will no longer be usable.

Also, windows no longer detects my phone so I can't connect to itunes to enable a Wi-Fi sync. So now there's no way to retrieve my photos

I visited an apple store today, they told me that it wasn't covered by a warranty and that it would cost around $300 to replace my phone. I think it's completely ridiculous that a manufacturing defect isn't covered by the warranty. Why should it be my fault that their manufacturers have bad parts?

Would it be feasible to open up the phone and attempt to replace the battery and bend back the metal housing?

Does anyone have any suggestions for fixing my phone and/or retrieving the photos from my phone in case if it dies on me?