I got a message from DPD that my package has been delivered to a pick-up station (even though I was at home). I did not receive a pick-up code, so the package has been sent back to Knirps. While this is clearly DPDs fault, I tried to contact the customer support of Knirps to at least get my money back. However, they did not respond to my mails for 2 weeks. I also tried to call, but after a while in the queue, they just hang up.