Corporation Bank — Not received the refund

Dear Sir/Madam,
We have not received our refund from Amazon . The refund amount is 690/-. But the customer service center of Amazon say that they have already refunded the amount to our account and they have provided us with a reference number:- [protected]. We have also checked with corporation bank but in our pass book there is no transaction of the refund. We kindly request you to sort this problem.