You can change your password to prevent this from happening again. To do so;
- Log into your account.
- Click My Account, within My Account you'll see Account Settings.
- Select Security. Beside the word Password, you'll see Edit. Click Edit and you should be able to update your account information.
If you have any further concerns, here's a link to get in contact with a Live Agent; https://turbotax.intuit.com/personal-taxes/online/