Hey. I have the same problem as many others. My Traktor Kontrol S4:s volume faders are moving by themself. I’ve sent maybe 5 tickets to them, and now my warranty have suspended. However I sent several tickets when the warranty was still active.
I’ve tried to write in NI forums, but still no answer.
If the above doesn’t work, try posting a thread in the following forum on their site itself. Include the Ticket number in the thread title. Thankfully I didn’t have to resort to that, but I’ve seen success for others.
My s4 is currently with NI in LA for the same issue. They were very responsive at first, but I had to send a few reminder emails before I finally got a response that everything had been processed and they were sending me a shipping label.
Hope it all works out for you.
edit: saw you already tried posting in the NI forums, maybe try again with the ticket number in the thread title?