I reported KNC for both of these
Unfair terms here: http://www.konsumentverket.se/Vagledning--kontakt/Gor-en-anmalan/Anmal-via-webben/Oskaliga-avtalsvillkor/
For failing to inform their customers the products were non refundable before purchase

Dangerous products here: http://www.konsumentverket.se/Vagledning--kontakt/Gor-en-anmalan/Anmal-via-webben/Farlig-vara/
400 watts a cube+ 1 PCI-e connector = FIRE. I uploaded a few pictures of burnt KNC connectors and cables

Here is the main page in case the links go bad http://www.konsumentverket.se/Vagledning--kontakt/Gor-en-anmalan/Anmal-via-webben/

I'll be reporting KNC to ARN as well http://www.arn.se/ .
I've got A LOT of stuff against KNC to put together so it may take a couple of days, but the more people that do it the more they will take notice.

I would also report them here http://www.econsumer.gov/english/report/overview.shtm
Interestingly this site is run by the FTC in the U.S, but it deals with international complaints. Probably a good place to file one.

Don't forget to report them to the police http://polisen.se/Kontakta-oss/Polismyndigheter/Stockholms-lan/
and file an application for payment with the baliffs https://www.kronofogden.se/Ansokaombetalningsforelaggande.html

 I'll be doing that if my invoice isn't paid by its due day this week.

This is an interesting read about the debt recovery process in Sweden http://www.millerrosenfalck.com/2013/01/debt-collection-in-sweden/

edit: Thanks VarChar, changed the links