I recently bought headphones from them (I will not tell you which ones, so that you do not think that this is an advertisement) and they broke after a week of use. I decided to contact their customer support team. I was lucky because https://onn-electronics.pissedconsumer.com/customer-service.html helped me with this
After the call, we quickly resolved this misunderstanding and they just sent me a new pair of headphones. Everything is fine!