Not quite sure if I want to aid you with this one since it will inevitably require me to ask for pics to the extent of the...damage. Also, please don't post a picture. Words will be enough for this post!
FYI, you're literally going to have to get your hands dirty on this one.
Yeah, really, this is going to be bad. I think you're probably going to need a whole new computer. Hopefully you can salvage the hard drives/SSDs and, if you're lucky, the video card. I don't even know how to dispose of the rest. There's no way Best Buy is going to take it and you really shouldn't be dumping it in the trash.