Amazon India — boat rockerz 255 product refund not done

Address:

#48 4th main 5th cross, Kaveri nagar mahadevapura, Bangalore, Karnataka, 560048

I was order head phone boat rockzer 255 quality defect so return on November 29th from that specific date to today I don't got redund I was tryed a lot contacting Amazon and bank customer care not yet got redund because I am requesting for charge dispute corporation bank customer care but no one solved .please kindly help me for my refund.