$client = new SoapClient($wsdl);
$client->__setSoapHeaders(
    new SoapHeader(
        $nameSpace,
        'Security',
        $secHeaderValue,
        true
    )
);

// The actual call
$response = $client->Complete($paramswebservice)

$responseHeaders = $client->__getLastResponseHeaders();
var_dump($responseHeaders);

/**
 * Returns the HTTP Status code of $response
 * @param string $response
 * @return string
 */
function extract_response_http_code($response) {
    $tmp = explode('n', $response);
    $array = explode(' ', $tmp[0]);

    return $array[1];
}