Amazon India — at&t seb50 dual-driver premiere in-ear noise isolating headphones

Address:	560067
Website:	amazone.in

I ordered a at&t seb50 dual-driver ear phone on 15feb2018. But i'm not satisfy with the product. I place r refund. Amazon send a pick up boy and take the ear phone. And mark the order "replacement completed".
But i still not refund my money. When i call customer care they say it is not possible to refund your money. I asked why they say we received another item from you.
So i need to take a action. Please give some positive result.