Repair for ND
Just use google and look for Tritec in Germany. They are the official repair shop and service point Kyocera handed over the Contax business when the company left the camera market. Tritec should be able to fix the issue.
By the way: When I got my ND I tried to use normal batteries. After a few "normal" shots, when current faded out, I got "destroyed" pictures looking very similar to what you've got. So think about cleaning the battery contacts of the beast, this could help.
P. S. Having worked with many cameras, the ND leaves a strange taste everytime I use it. Being limited to ISO 400 sucks. And the AF also is a kind of bad joke. So I shoot architecture and portraits in bright sunlight with it because for action it seems to be the wrong machine...