Hi @mcmarmite,
Welcome to the Roku Community!
We understand that you have sent the product to the wrong address, and we appreciate you letting us know about this. We advise you to contact the return carrier to request it be "returned to sender."
For more information, you can check this support article Roku devices limited warranty and End User license Agreement.
Thanks for your understanding.
Kind regards,
Bernie
Bernie D.
Roku Community Moderator