At this stage of the Answer HQ beta we are only able to provide support in English. Therefore we kindly ask to use Answers HQ in English only and apologize for any inconvenience this may cause. We plan, however, to extend the service to multi languages later on. So stay tuned for updates.
It looks like your product code was already redeemed on another Origin account in the past. I would suggest contacting a Game Advisor at https://help.ea.com/contact-us (or German phone: http://www.ea.com/de/1/kundendienst-hotlines) they should be able to locate your old account.
Thanks.