What is contact number for Hyperli

I bought a cellphone from Hyperli which was delivered on 1st November 2017. Upon the first time it was being charged the phone batyery swelled up. I have been trying since 6th Nov (within the returns/refund timeframe) to send emails and call Hyperli to come collect the defective phone. There has been no response. I want a full refund for the phone. I no longer want it. How do I get hold of them???