Amazon sqs node.js worker

I've created a node.js worker that processes my jobs stored in the queue, and every time a jobs comes in sqs service I get a POST request to my node.js worker, after that I try to read the messages from the queue, but the only thing I get is :

    {"ResponseMetadata":{"RequestId":"9d6121e0-4241-5bc8-a000-6ca41ae431f9"}}

My question is, why can't I get the messages (sqs says that they are in flight), and the second thing is I know I get my message when SQS service makes a POST request, then why is there no RecipientHandle in that request to delete the message?

my worker.js

AWS.config.update({
    accessKeyId: AWS_CONFIG.ACCESS_KEY_ID,
    secretAccessKey: AWS_CONFIG.SECRET_ACCESS_KEY,
    region: AWS_CONFIG.REGION
});

var sqs = new AWS.SQS();

var i = 0;
router.post('/', function(req, res, next){

    if (!dataIsSet(req.body)){
        req.send(569).end();
        return;
    }
    var msgId = req.header('x-aws-sqsd-msgid'),
        name = req.body.name,
        message = req.body.data;

    console.log('Headers : ');
    console.log(JSON.stringify(req.headers));
    console.log('============ Request came in ============' + (i++) );
    res.status(200).send('Msg');
    var data = {};

    sqs.receiveMessage({
        QueueUrl: AWS_CONFIG.SQS.QUEUE_URL,
        MaxNumberOfMessages: 10,
        VisibilityTimeout: 20,
        WaitTimeSeconds: 0
    }, function (err, response) {

        console.log('============ Message from queue : ============');
        console.log(JSON.stringify(response));
        if (err) {
            console.log(JSON.stringify(err));
            //callback(err);
        } else {
            console.log(JSON.stringify(response));
            data = response;
        }
    });

});

Thanks!