How To Get Faulty Sensors Replaced

I recently bought a couple of motion sensors from the Samsung online store here in the UK. At least one of the motion sensors was DOA. I have done the usual - new battery / reset etc - but it remains dead. How do I go about getting a replacement. Samsungs online chat is down and the email templates do not list Smartthigns as a product option?

Anyone know?

Thanks

Jon

Just email support@smartthings.co.uk