First, see what's the status of the transaction. If it says "pending," it will take 7-8 days for the money to be sent back to your account. If not, carefully look over your bank records to make sure you remember the exact amount that was taken out and the date and time of the transaction.

Contact Kotak Bank's customer care and tell them about the whole situation; they will raise the dispute for a failed transaction.

If Amazon received the money, the bank will provide the Transaction Reference Number (ARN).

Contact Amazon customer care and explain the whole situation to them. Give them the order number, the date of the purchase, and any error messages you get. Send them the ARN and some other information, then ask for a return or the order to be filled.

If nothing else works, email Kotak Bank's customer service and ask for a refund. Send them all the proofs, like screenshots, bank records, and information about your Amazon order. Then wait 30 days.

If the bank is not able to resolve your issue, then write to RBI Ombudsman through the CMS portal (https://cms.rbi.org.in/).