Union Bank Of India — Refund money stuck with bank

Returned a tshirt on amazon which was paid using my bank's debit card related to a union bank account that i closed few days after ordering that tshirt. after that i returned the tshirt the refund was processed on 9th nov and now it shows that the refund has been done by 14th nov but i havent got the money. reached out to the bank's branch and they say they dont know anything about the money since the account is closed. contacted amazon customer care and they said to raise a complaint here.
relevant details here:
Refund Reference # 30005403150309083754896
bank and branch- Union bank howrah fazir bazar branch