If you feel that your account has been hacked or compromised in any way - contact Gemini Support here and select Fraudulent Activity followed by My Account Is Compromised in the next dropdown menu.
In your email, please provide your full name, the email address and the phone number that is associated with your Gemini account. If you are contacting us using an email address that is not associated with your Gemini account, please let us know and also specify the email address that is associated with your account.