If your return is returned to you this is most likely because of missing documents.
To re-send the return you will need to submit a new return request at remarkable.12return.com. Keep in mind that you will need to book a new pickup for your return as well as printing a new shipping label. Upon the hand-over to DHL please make sure to hand over the three copies of the proforma invoice and the second part of the shipping label to the courier. You can find the shipping label under the tab "Shipping" and the proforma invoice under "Return information" under "My returns" in remarkable.12return.com, or in the email sent to you after the return was authorized.