I've been attempting to get a refund from them for a product and they use every trick in the book to not refund any money.
They claim it takes 3 to 10 days to process a refund. In practice what happens, is they wait 10 days then look for some additional info they need from you, claiming they cant send the wire, then they wait another 10 days after you give them what they want, then look for more info they need from you. I suspect they keep this up until its "too late" to refund anything.
So you actually mean you requested a refund and didn't provide enough information. Plenty of people have dealt with KNC customer service with good results. We even have someone who works there posting here on a regular basis. They also sold many thousands of machines which have done well for many hundreds or thousands of customers. Compared to all the other asic manufacturers they are angels.