I am sorry to hear that your combination cannot be found to open your safe. Be assured though that this is a common question on our site as you are not alone in this.
The recommended way to retrieve your combination is to contact Sentry directly as they will be the only firm in which to send this to you. No one will have your combination because of safety concerns other than Sentry. Simply contact the company at the link below and follow the instructions for the proper way to retrieve your combination for your safe: