The provider of the payment gateway is Comgate, a.s. https://www.comgate.cz/cz/platebni-brana
On this site you can use card payments and bank payment buttons with a basic explanation of the payment process here:
Contact information for Comgate, a.s. for any complaints or payment inquiries:
Comgate, a.s.
Gočárova třída 1754 / 48b, Hradec Králové
E-mail: platby-podpora@comgate.cz
Phone: +420 228 224 267