German forum is at http://community.eu.playstation.com/t5/Deutsches-Forum/ct-p/38
But plus is linked to your account, not your console so I guess you mean your account is activated as primary on another console?
You can fix that at https://account.sonyentertainmentnetwork.com/liquid/login.action
or CALL support
https://www.playstation.co/m/get-help/contact-us