Been unable to use the wireless headset as faulty!

I ordered wireless headset for my Daughter for Christmas, which were faulty - unable to charge them as the part doesn't fit into the opening meant for the charger. I've emailed twice and sent 2 WhatsApp messages but have had no response. There is no telephone number nor physical address on their website. How do I go about getting a refund and returning this faulty product? Am SO disappointed and will never use them again.