Troubleshooting can't connect my old Kindle 3G

Hello, I'm new in this so need some help please.
I've just repair an old Kindle 3G that my wife had forgotten, everything went right till I try to enter my amazon account, it keeps telling me that the user or password isn't right.

I chat with amazon service and, after many attempts, resets, etc. They tell me there's nothing I can do, the device won't connect and my amazon ebooks won't pair (and give me 15% disccount for a new kindle).

I'm writing in this forum to find help if there's something I can do, via jailbreack, hacks or anything, thanks in advance to anyone who reads my sad kindle history.

Sorry if something isn't well written, english isn't my native lenguage.

Thaks again!