Help with SBI bank & Amazon refund dispute.

I ordered some items on Amazon fresh and they didn't get delivered for like 5-7d. After which I tried contacting Amazon. KEEP IN MIND I DIDN'T RECEIVE ANY MAIL FOR REFUND INITIATION. For months the amazon support blamed it on the bank and after contacting bank, the bank said there are no issues on our end, if we recived anything to your account it must at least appear in the bank statement(even if there is a discrepancy b/w statement and what acctually got added to bank). Now after contacting them many times today they are refusing to send a mail or the amount. And here I am asking for help.