Department ID field's default_value is incorrect

  $form['widget']['livehelperchat_department'] = array(
    '#type' => 'textfield',
    '#title' => t('Department ID'),
    '#default_value' => variable_get('livehelperchat_department_id', ''),
  );

As you can see, even though the field is called 'livehelperchat_department', the default value is set to 'livehelperchat_department_id'. This means even though the value saves correctly on submit, the next time the configuration form is viewed the value will be gone.

I'm working on a patch.