<?php
class Gta_FindPaymentGateway_Model_Observer
{
public function paymenter($Observer)
{
$currentCustomerGroup = (int)Mage::getSingleton('customer/session')->getCustomerGroupId();

if(($Observer->getMethodInstance()->getCode() == 'payubiz') && ($currentCustomerGroup !== 4))
{
$result = $Observer->getResult();
$result->isAvailable = false;
}
}
}
?>