Expected response code 200, got 403

[jaffarhussain1011]

Hi,

I am using GDATA since 1 year for google contacts and this was working fine till yesterday.

Now i am getting this error whenever I tried to connect.
Expected response code 200, got 403 usageLimits rateLimitExceededUnreg Rate Limit Exceeded. Please sign up https://code.google.com/apis/console .

I am using following code:
require_once("Zend/Gdata/ClientLogin.php");
require_once("Zend/Gdata/Contacts.php");
require_once 'Zend/Gdata/Query.php';

class GoogleContacts extends Zend_Gdata_Contacts {
public function getContactListFeed($last_sync_date = '',$group){
$query = new Zend_Gdata_Query(self::CONTACT_FEED_URI);
$query->maxResults = $this->maxResults;
$query->startIndex = $this->startIndex;

    return parent::getFeed($query,'Zend_Gdata_Contacts_ListFeed');
}

}
$client = Zend_Gdata_ClientLogin::getHttpClient($user, $pass, 'cp');

$service = new GoogleContacts($client);
$service->setMaxResults(100000);
$feeds = $service->getContactListFeed(str_replace(' ', 'T', $lastSync) . ".000Z",$groupId);
$ids = array();
foreach ($feeds as $feed) {
//process over here
}

Looking for help.
Any idea what went wrong and how to fix it??