There is a so-called cooling-off period of 14 days within which you can return the product without giving a reason. The product can only be returned unused (before it is assembled and other usage) and if possible, in its original packaging and including a return form. Orders can only be returned when the return form, which you can download below, is completely filled in and attached.
For returning the order, the shipping costs are for your account, so make sure that your shipment has sufficient postage. Also make sure that the returned goods are packaged well, as any shipping damage is at your own risk. Bringing the product back yourself is also possible, but only after making an appointment. Return payments are only remitted to you by bank afterwards.