Using doctrine in Symfony2 command

I have a command connecting to an external database and loading the data into my application's database. The command will run periodically as a cron job. However, I run into the following problem when I run the command in the console:

PHP Fatal error:  Call to undefined method Symfony\Component\Console\Application::getKernel() in E:\www\project\vendor\symfony\symfony\src\Symfony\Bundle\FrameworkBundle\Command\ContainerAwareCommand.php on line 43    

I followed the tutorial here on symfony's website to the letter.

Here's the service definition:

app.command.get_transactions:
    class: AppBundle\Command\TransactionsCommand
    arguments: [ @doctrine.orm.entity_manager ]
    tags:
        -  { name: console.command }

Here's my command code:

<?php

namespace AppBundle\Command;

use Symfony\Bundle\FrameworkBundle\Command\ContainerAwareCommand;
use Symfony\Component\Console\Input\InputArgument;
use Symfony\Component\Console\Input\InputInterface;
use Symfony\Component\Console\Input\InputOption;
use Symfony\Component\Console\Output\OutputInterface;
use AppBundle\Entity\Transaction;
use AppBundle\Entity\TransactionSync;
use Doctrine\DBAL\DriverManager;

class TransactionsCommand extends ContainerAwareCommand 
{
    protected function configure()
    {
    $this
        ->setName('transactions:get')
        ->setDescription('Import transactions')
    ;
}


protected function execute(InputInterface $input, OutputInterface $output)
{
    $em = $this->getContainer()->get('doctrine')->getManager();
    $q = $em->createQueryBuilder();
    $q->select('t')->from('AppBundle:TransactionSync', 't')->orderBy('t.id', 'DESC')->setMaxResults(1);
    $sync = $q->getQuery()->getResult();

    $em1 = $this->getContainer()->get('doctrine')->getManager('rnr');
    $conn = $em1->getConnection();
    $query = "SELECT id, merchant, client, phone, traderTransIdent AS member_id, transaction_id, transaction_type_id, value AS amount, points, DATE_FORMAT(STR_TO_DATE( transaction_date, '%d-%m-%Y' ), '%Y-%m-%d') AS transaction_date FROM merchant_transactions WHERE id > ". $sync->getId();
    $stmt = $conn->prepare($query);
    $stmt->execute();
    $results = $stmt->fetchAll();

    if(count($results) > 1)
    {
        $ts = new TransactionSync();
        $ts->setStartTime(new \DateTime());
        $id = 0;
        foreach($results as $result)
        {
            $transaction_type = $em->getRepository('AppBundle:TransactionType')->find($result['transaction_type_id']);
            $member = $em->getRepository('AppBundle:Member')->find($result['member_id']);

            $transaction = new Transaction();
            $transaction->setAmount($result['amount']);
            $transaction->setPoints($result['points']);
            $transaction->setClient($result['client']);
            $transaction->setPhone($result['phone']);
            $transaction->setTransactionId($result['transaction_id']);
            $transaction->setTransactionDate(new \DateTime($result['transaction_date']));
            $transaction->setTransactionType($transaction_type);
            $transaction->setMember($member);
            $em->persist($transaction);
            $id = $result['id'];
        }

        $ts->setLastId($id);
        $ts->setRecords(count($results));
        $ts->setEndTime(new \DateTime());
        $em->persist($ts);
        $em->flush();
    }

    $output->writeln($text);
}
}

According to the accepted answer here and many other places online I have seen, extending ContainerAwareCommand should solve this but I still keep getting the error. Please assist in pointing the step I missed, I'll be very grateful