delete user with negative balance on login

/**
 * Block Negative Balances
 * Delete users that try to login to an account that has a negative balance.
 * @version 1.0
 */
add_filter( 'authenticate', 'mycred_delete_users_with_negative_balances', 990, 3 );
function mycred_delete_users_with_negative_balances( $user, $username, $password ) {

	// Make sure myCRED is installed
	if ( ! defined( 'myCRED_VERSION' ) ) return $user;

	// The point type we want to use
	$type    = 'mycred_default';

	// Load myCRED
	$mycred  = mycred( $type );
	$account = get_user_by( 'login', $username );

	if ( isset( $account->ID ) && ! $mycred->exclude_user( $account->ID ) ) {

		$balance = $mycred->get_users_balance( $account->ID, $type );
		if ( $balance < 0 ) {

			// Delete user
			wp_delete_user( $account->ID );

			return new WP_Error( 'mycred_negative', __( 'Account Closed' ) );

		}

	}

	return $user;

}