Consumer Redressal

I have Ordered a Slim beauty fitness massager Oder No - 2015-04-16-060682 on 16th April, the product was delivered on 30th April. On recipt, the Adapter was not working so I raised a complaint on SHOP CJ for which there was no response for 2 weeks. On calling repeatedly they said I need to contact the product customer care?? The product customer care are asking me to bear the courier charges of INR 600 on the product value of INR 1600?? why should I pay this amount for a defective product? What is the responsibility of SHOP CJ?? I need to file a legal complaint, someone suggest me please.