If you have lost your SIM number and need to retrieve your account, you can start by resetting your security settings. To do this, you can use the security_reset@gate_official_bot command in your chat. This will allow you to reset your security settings and regain access to your account. If this does not work, you can also create a support ticket by using the ticket@gate_official_bot command. This will allow you to explain your issue in more detail and receive help from the customer service team.