They should have been refunded by ebay, not you. In which case they do not need to return the item but if you want it back see if you can send them online postage or ask them to return it and you reimburse them.
If they haven't been refunded yet ask them to open a return case using the reason "Item damaged". If possible respond on the case that according to Global T&Cs you are not responsible for loss or damage in transit after it has arrived safely at the UK hub. But that should be self evident and ebay will issue the refund.
