Amazon.in - Cashback Not Received

Hello sir on *th June I ordered pritec * piece of opc drum From Amazon worth rs ****.I ordered this item for receiving cash back offer to get ***rs cashback.My Order No is #***-*******-*******.

Later I found the my package is returning to seller when I enquire about this one of Amazon agent (Shailendra) told me that it's returning because item damaged during transit.
As per Their policy cash back not be given if item returned.But when I asked whether I will get cash back or not Shailendra(Agent)
Told me that I'll get cash back bcoz item returned due to damaged by their part.Here
I'm not involve for returned for my item.
Later On **th january my item returned but I only get refund not got cash back when I enquire agent(shoundharya) told me they can't processed cash back.
Sir my problem is I didn't got cashback of *** rs my item damaged and returned **** due to them not due to mine.So please help me getting cash back that I entitled.