How to file consumer complaint in Germany

Greetings everyone,

We had bought two microcontrollers from Sunrise Systems, GmbH, Germany 
(http://www.sunrise-systems.de/index_e.htm) and wired them the requested 
money for product delivery about 4 months back. We had agreed via email 
that the product will be delivered in 2-6 weeks upon the receipt of 
money (I have email trails as proof).

Since then, Susrise Systems, GmbH, has not complied with our request. 
Also, we have repeatedly sent requests to cancel our order if the 
product is not ready.

I wanted to ping this forum to find out possible ways to get our money 
refunded from Sunrise Systems, GmbH. What can we do to perform this? We 
are based in California, US.

All help is appreciated.

with regards,

Bobby Sardana.
[EMAIL PROTECTED]