Amazon India — Not accepting my return

Hello

I have ordered Casio G-Shock 2100 in Rs 9195 and they delivered it on time after unboxing my order i found it was used and found different g-shock cover box
then I call the customer care and told them I got used watch and they took my complain and told me please wait 4days for our team to investigate . Then after four days I call them back again and they told me we have sent you the right product we can’t return or replace, after that I call them so many times their response were same

Please request you to return my product !!