Nykaa.com — Not receiving refund

I had order an item in Nykaa Fashion and due to incorrect fitting, i had assigned for return. on 2nd August it got approved. Order ID - NYK[protected]
Since then no pickup has happened nor the refund. I got multiple message saying pick-up is cancelled (no reason mentioned). I created a issue at their site, called the helpline. No action is taken.
Looks like Nykaa doesnt want to pick the item, hence doesnt need to refund the amount. Absolutely unacceptable behaviour.
I am waiting for refund of 748.