You can use this service to reset your Battle.net password, which will remove most account locks.

Troubleshooting steps for resolving lock ups in Diablo III.

Troubleshooting for error 315000

Troubleshooting steps for crash problems

Troubleshooting for game crashes with error "The application encountered an unexpected error"

Troubleshooting for Battle.net desktop app crashes.

Troubleshooting steps to help you connect to Diablo III

This error message appears while logging in to the game with the message that the player was disconnected from the server.

What to do if you are seeing an error after starting the game

What to do if you can't open the Battle.net desktop app, and there are no error messages when you try.