United Bank Of India [UBI] — Refund from Amazon do not credited to my bank account

On 22 October 2020 I cancelled a prepaid order on Amazon and in the next day means on 23rd October they released my refund amount of RS -2036 but its been 12 days I don't get my refund amount in my bank account.

Amazon says that they released the payment on 23rd October 2020 and the payment is successful. The Refund amount may stuck in UPI or at Bank. They asked me to contact my bank.
and gave me a Refund Reference Number as ( RRN[protected].
In the amazon app, at "Your Transactions" option it is showing that refund is already credited on 23rd of october.

But the bank manager is saying that they do not get any amount from Amazon. And when I asked for chare dispute form then they refuse it and says we cant do this.
What should I do???
Please help me