Common problems with Gmail 2-Step Verification
My Mobile phone was lost or stolen
If your Mobile phone was lost or stolen, Google strongly recommend that you should change your Application Passwords and change your Gmail Account password. This will help to prevent others from accessing your Gmail Account from your mobile phone. you can call (800) 674-2913 for quick Gmail customer service
You can try several ways to get back into your Gmail account, depending on your conditions.
You can Use backup options
If you’ve lost access to your primary mobile phone, you can choose to have codes sent to backup phones. In addition, you can use one of your printable verification codes to sign in your Gmail.
Sign in from a trusted pc
If you’ve previously log in from a pc and checked that the computer should remember you, you might be able to log in from that pc without a verification code. Once you’re in your Gmail account, you can turn off 2-Step Verification process until you can again get Gmail account verification codes.