I've bought loads of stuff from them, they're definitely not a scam. They're just not great on answering mails, unfortunately. Last time I had to send a mail to several different addresses to get a response.
These were:
KDH-Datentechnik@t-online.de
bestell@kdh-datentechnik.com
info@kdh-datentechnik.com
Please don't flood them with mail because you don't get an answer in a day. One to each these addresses, and a wait of a week or maybe two, will be most likely to get you a reply.
