First, this is a forum for authors. KDP folks hardly ever look here.
So your best bet is to do a Contact Us (at the bottom right of this screen) and give the KDP folks all the relevant information.
One other thing: Your posting count indicates that this is the first time you've ever posted to the forums. If this is NOT SO, then you may have accidentally created a second Amazon log-in / password combo. If that's the case, try logging in with your original e-mail/password (and do NOT rely on the browser to auto-fill the password for you--key it in yourself). Update: This is probably not the case, as your registration date is not recent.
Best of luck.
Another thought: You could go to your Reports page and press the Payments link to see what information is there.