Amazon India — Lyf Water F1s

Address:	Howrah, West Bengal, 711101
Website:	amazon.in

Hi,
I purchased a Lyf Water F1s phone on 04/05/2017 through COD. Later on I find that the phone has some battery issues as battery was not working properly, even when the phone was not in use the battery use drain very quickly. I never removed the charging plug of the phone untill and unless it was 100%, but the issue remained the same.
So I placed a return and refund on the amazon website on 09/05/2017 and it showed that I have one product to return, I even provided the bank account details for the refund. But when I called the customer care they kept on saying that I never filed the return and refund and the refund can't happen.
So it means that my Rs. 7968 has gone for a toss and I won't be getting that. If the return was not going to happen then why the order page showed that I have one product to return.
I am totally dissatisfied with the service from amazon.in
Now now should I do? The uestion remains