1. You do not have to pay for the courier to return the goods. Essentially, the clothes were delivered to you for you to do something gratuitously for the bailor or major fashion company. The relationship of bailment was created between you and the fashion house in relation to the goods You were obliged to keep them safe, but you were not obliged to return the goods at your expense. In this regard, you are in no different situation to a launderette who is given clothes to launder them for their owner for free. The clothes arrive by courier. But there is no obligation on the launderette to pay for a courier to send the clothes back to the owner of them. The onus is on the owner of the clothes to either come and pick them up or to forfeit them. So here, you have no obligation to pay for a courier to send them back as there was a gratuitous bailment in place for you to photograph the clothes. Nothing more.
Thank you very much. I have emailed them and have politely insisted that they do so.
2. That is a good way of handling it. Stress the gratuitous nature of the services provided and ask them would they consider covering the costs of the models which you used.
Thank you. your prompt advice is greatly appreciated.