Amazon.in — Phone was ordered, then returned they are not returning back money

Address:	Gurgaon, Haryana, 122018
Website:	www.amazon.in

I had ordered the moto g4 plus from amazon.In order id order #[protected]
I had ordered on 18th may 2016
I receive the product as expected on 23rd may 2016. Paid in cash but the delivery boy didnt take my signature. He said its okay
But in my order list it shows that i have not received the product but returned it
Then i contact amazon that in my order list it showing i have not received the product but i have received it.
After few days they tell me to return it. They create a return ticket
I return the phone on 30th may 2016 but now they are saying they have not received the product. And they are clueless about the phone
I have paid 15, 000 /- in cash for the product
And they are denying it trying to make me understand that no return or replacement can be issued
) i have paid 15, 000 for this product to your deliver guys
2) i have this product you can match imei number as 2 phones cant have same imei number
3) i have sent pics of box, phone box, phone imei number

I had inserted my sim in that phone and i have used that phone for 7 days. Now after returning they are denying
I have all the images as proof

But they are not ready to listen. I have used that phone with my sim. As its imei number can be tracked and it can be checked when this phone was used and which number was used in this phone

They are neither returning my money or phone. Disclaiming all liabilities saying that they have neither deliver it or dont even know when it got returned.
Since it was cash on deliver so they cant do anything.