[Resolved]  Amazon India — defective item received, and amazon is not responding

I bought an air cooler from amazon india. And unfortunately the item turned to be defective.
When the product was ordered, it was promised to do 100% replacement or return if the item turns defective. And now there is something that the seller is asking to do self return, which i cannot do it as my parents are old and they cannot do the courier. I am way farther from them.
And i want amazon to respond to my question. If this item was supposed to be made self return, then why does the product show 100% guaranteed return by amazon in case the item needs replacement or defective.
I dont mind if amazon is ever going to