Amazon India — not ordered but got delivered and collected amount

Address:

Chennai, Tamil Nadu, 600087

I have not placed any order for Headphone. But it have reached my house during my absence. we regularly by from amazon so in my house they had paid and collected it. Since the box packing is of Amazon. And it was delivered through india post.

I have got a message from amazon
"Important notice, Thanks for messaging your address. please receive the discount voucher with FREE HEADPHONE by paying 1050/-rs and collect the voucher from the nearest dealer mentioned in it. NOTE: In case if you failed to receive it, you will be sent legal notice with a fine of 2, 499/-rs for violating the rule of ordering online and for not receiving it. For more details call [protected]"

When i called this number they said they will check and inform immediately but they did not revert back.

Invoice No: DHYK89546621
Shipper Name: Madhu B V, Amazon Seller1, C/o Mobile campus, shetty street, chikmugalur, -577101. Ph- [protected]