You can use the following letter mentioning details of the savings certificate. To The XYZ bank (Address)
Sub: Loss of my savings certificate no…………. dated…….
With reference to the subject, I regret to inform you that the savings certificate bearing no…… as mentioned above, is unfortunately misplaced or lost. I have tried my best to search the same but all my efforts went in vain as I failed locate it.
Under the circumstances, I request you to issue a duplicate certificate at my cost which you can recover by debiting my account(if you have an account with the bank) or inform the amount which I am ready to deposit forthwith.