What company is that ? I don't see any real contact gmbh adress. There is
Sipgate dont accept reseller DID.(Only hardware resell) Speakup dont have Aachen DID numbers. Lot of German DID number providers, But not specially for Aachen.http://www.sipgate.de, or try http://www.speakup.nl/
@outbox.de: contact info on every german website via imprint: http://www.outbox.de/kontakt/impressum/