defective product delivered and no redressal of complain and no refund

I ordered Beats mini bluetooth speakers from this particular site. As soon as I opened the parcel, I found that it wasn’t working and was defective. It wasn’t original even. The buttons weren’t working and the net of the speakers was also broken. I rang up the customer care center and they assured me that the courier man will come within a week to collect the defective product. But now its 35 days and no response has arrived to me yet. I made continuous efforts to remind them again and again through emails and also called them 8 times to re-look at my complain and sought a remedy for that. But despite having taken so much of efforts, no response came.