Username

A username change like this only occurs if a user initiates it. I recommend you to immediately change your password for both Minecraft and your Email Account as someone may have guessed your login details.

You can change your name again 30 days after it was changed, though you will have to wait an extra seven days to change it back to the original name. No, there is no way around this - please prevent this from happening again by making your account more secure.