I purchased a steam key on kinguin.net. It was stated to be invalid in the steam app. I have contacted kinguin numerous times and have received no response at all. So, I am effectively out this money - there is no recourse. I have had to dispute at paypal and with my credit card. My recommendation is to avoid this site if you value your time and if you don't want to enter into a long dispute process. This business is unreliable and sells invalid items. Zero stars. Avoid this site.
UPDATE: 12/30/20 - received refund. However, this was only after a lot of time and effort spent starting on 12/17. If the site would communicate more promptly a lot of the negative experience could be improved.
Dear Martin,
We are very sorry to hear about your experience with our Support Team.
Our store has been experiencing highly increased traffic and we are doing our best to reach all our customers as soon as possible. We hope to lower the waiting time soon.
We would like to reassure you that we sell valid keys, and any key proven to be invalid is either refunded or replaced. We never leave our customer without a reply, although it might be necessary to wait a couple of days for it. We are very sorry about the inconvenience caused!
Best regards,
Vera