It is highly unlikely that someone gains unauthorised access to a Miniclip account, or change its email unless that account is Facebook connected, as account changes can only be done by our Support team.
If someone else played using your account, we recommend you to change your password. Here you will find a link that you can use to change the password (doesn't work for accounts only connected to Facebook).
If your account is Facebook connected and your Facebook account is compromised, that is not of Miniclip's responsibility. However, if this happens, please change your Facebook account password as fast as possible. If needed, check the guidelines how to behave in those occasions.
Also be sure to end session of every device that is not yours right after changing the password.
If your Gmail is having an issue like this, you can reset password or check the guidelines about how to recover a hijacked account.
Take into consideration that forced sign out from the game is not a guarantee that you can fully recover your account, so always remember to log out whenever you use a device that is not your own and do not share your account with no one.
Once changes are applied to your Facebook or Google account, they will automatically be applied to all games you use it.
Please remember that you are responsible for your account and you should not share the account details with other people.