quickblox php get unread messages list

I am trying to get only unread messages list (not count) from a dialog. There is no such request in the documentation of QuickBlox. This is my function but it returns nothing:

function getUnreadMessages($login, $password, $dialogId, $userId) {
    $session = quickCreateSession($login, $password);
    $token = $session->token;
    $curl = curl_init();
    curl_setopt($curl, CURLOPT_URL, 'https://api.quickblox.com/chat/Message.json?chat_dialog_id=' . $dialogId . '&read_ids[nin]=' . $userId );
    curl_setopt($curl, CURLOPT_RETURNTRANSFER, true);
    curl_setopt($curl, CURLOPT_SSL_VERIFYPEER, false);
    curl_setopt($curl, CURLOPT_HTTPHEADER, array(
      'Content-Type: application/json',
      'QuickBlox-REST-API-Version: 0.1.0',
      'QB-Token: ' . $token
    ));
    $response = curl_exec($curl);
    if ($response) {
        return @iconv("ISO-8859-9//TRANSLIT", "UTF-8", $response);
    } else {
        return false;
    }
    @curl_close($curl);
}

You can get all the message from QuickBlox ,where you get read and unread status of the message and which can be easily managed.I hope this will help you ....