Amazon India — return not pick up after taking follow up - tracking id [protected]

Address:

500032

HI,

I have ordered Electric blanket . and after checking it was not work as expected . So I have raise return request. And they have accept it and giving me below details.
Pickup Tracking id : [protected].
Return time : 5th Jan 2019, between 15:00 to 18:00.
NO one is coming for pickup . I have contact them 2 -3 times in customer care. but still they are not pickup my order . Now they said window is expired and you need to courier it.
Why should I courier it ? They need to pickup and refund my money .
They have approved my return request .