I have a question about my payment, who should I contact?
In addition to PayPal and AmazonPay, we also work with the payment service provider Unzer. The payment methods Sofortüberweisung, purchase with credit card and purchase on account are processed via this provider. If you have any questions about a rejected or failed payment process, please first contact Unzer support at:
https://help.unzer.com/kb/de/endkunden-support-28937
https://www.siku.de/en/Frequently-asked-questions/Onlineshop/I-have-a-question-about-my-payment-who-should-I-contact
https://help.unzer.com/kb/de/endkunden-support-28937