It happens I have a new identity ... no, someone has my credential or such for using my twitter account. Twitter does not reply, there is no team that can fix it.
Problem with twitter is that it is insecure by design. You indicate an email address and confirm it, at registation time, or whenever you want.
Well, now? If you want to change email address you have to confirm it with the old, confirmed one, email, you are guessing ... no. You have to verify the new email address with the new email address!!