Amazon India - Pickup taken but refund not given

I had placed order from amazon and had sent them this email as well.

I had placed an order from amazon carrying order no. ORDER #
***-*******-******* i.e.Protoner PR*IN* *-in-* Blend Multi Bench for
Home Gym on **th October ****. I received the product on **st October.
The product was of awful quality therefore I wanted to return it.
I opened up my amazon app and the only option available was for
replacement so i ordered a replacement on **st afternoon (THEREFORE A
PICKUP HAS BEEN REGISTERED). On **st Evening i called up amazon and
requested them for a refund instead of replacement because i didn't
want the same product again. The amazon registered my request and told
me to wait for * days and your pickup will be initiated.

On **nd Morning the product was picked up from me. Afterwards i
received a message that my replacement has been cancelled and a fresh
pickup has been generated for refund of the product. ( But i had
already handed over the product). On **th a pickup boy again came to
pick up the item so i told him that the pickup has already been
completed.

I called up amazon on **th Oct **** that in my app it isn't showing
that the product has been picked up. They told me that i can see your
product has been picked up on **nd for replacement purpose that's why
it is not showing. Once it will reach the fulfillment center your
refund will be initiated and i have to wait for *-* days for this.

Today i called amazon again and they told me the same thing ((Once it
will reach the fulfillment center your refund will be initiated and i
have to wait for *-* days for this. Max by Nov **))

On *th Nov i again called up amazon and they don't have any update on it. They are just saying that seller is not replying to emails and calls

Therefore they are not providing me with refund