How to get a case number for license transfer?

Dear all,

I would like to transfer my Creative Suite CS6 Production Premium license to a new owner. After some internet searching I already found the instructions at

http://helpx.adobe.com/de/x-productkb/policy-pricing/transfer-product-license.html#main_License_transfer_process

Now I got stuck at the point to obtain a case number. Every time I click on "Contact us", the only option I can choose is, to write to the Adobe community forums.

Can anybody give me some detailed instructions how I can get a case number?

Thanks in advance!