company not repair or replaced faulty product

Location/place: new delhi

Name of company/service: homeshop18

Dear Sir,
i have purchased a mobile(micromax x-550)from homeshop18,but the product was found faulty,when i told to homeshop18 customer care,they said please return the product.

i have sent product by TNT courier on 25.06.2012,but till date no repair/replace has done.the product was purchased by advance payment.

please help in this matter,as the company official didn’t given any sufficient answer & feed back

regards
vimal bhasin