the last time i had to return a phone for non-functionality after i'd gained administrator access, they didn't even look at the phone before they gave me a replacement. that's what my money's on here, too, especially with a broken screen and no usb function. they probably won't even attempt to repair it, it's just not worth it. they'll try to recover the precious metals from it and be done.
no promises of course, but that's my guess.