Shoppersstop.com — Refund not processed

I purchased one sunglasses from shopper stop online on 24th September, 2022 and get the box on 27th September, 2022, As the item is smaller in size so raised a return request i next 5 mins after receiving the item.
And the Item was picked up on 30 September and got the mail that the item picked and after quality check my amount was refunded back.
Now they are saying from past 2 months that they received the empty box, but when the item was picked up courier person checked everything and the item was there in box in front of me .
Its almost 2 months now they keep on saying they received empty box as its not my fault if they received empty box or the item was misplaced in between.