(Strangely, the "contact us" link at the bottom of the page has been disabled.)
The reason for the button being disabled is because it's CHRISTMAS so no-one will be around to mod it however you can contact them directly if it's urgent by E-mail at email@example.com
i don't however know if there phone lines are working but her's there number just in case +49 (0)40-60080990. Please be advised it's a german game so if you phone them you may have language difficulties. If you E-mail them your be fine.