I have been a lurker for a while now but recently joined to the forums after I bought a Note 10.1 with bad firmware on eBay.
Hopefully someone can help me and then I can pass that knowledge down!
-Justin
Welcome to the forums! Did you knowingly purchase the device with bad firmware? If not, return it. Otherwise, see what was done to it and possibly contact Samsung for repair or replacement, if its covered under a warranty.