Indian Bank — refund has not been credited in my bank account

I have returned a product rs357 on 27 april to amzon whose payment i made through my indian bank debit card. Amazon has initiated the refund on 27 april as shown in my amazon account and provided me refund refernce number[protected]. But indian bank has not yet credited my account. I called indian bank costumer care, they want utr number but amazon costumer care do not provide utr number. None of them is solving this issue.