$this->load->model('account/customer_group');

    $customer_group_info = $this->model_account_customer_group->getCustomerGroup($customer_group_id);

    $this->db->query("INSERT INTO " . DB_PREFIX . "customer SET customer_group_id = '" . (int)$customer_group_id . "', store_id = '" . (int)$this->config->get('config_store_id') . "', language_id = '" . (int)$this->config->get('config_language_id') . "', firstname = '" . strtoupper($this->db->escape($data['firstname'])) . "', lastname = '" . strtoupper($this->db->escape($data['lastname'])) . "', telephone = '" . $this->db->escape($data['telephone']) . "', custom_field = '" . $this->db->escape(isset($data['custom_field']['account']) ? json_encode($data['custom_field']['account']) : '') . "', salt = '" . $this->db->escape($salt = token(9)) . "', ip = '" . $this->db->escape($this->request->server['REMOTE_ADDR']) . "', status = '1', approved = '" . (int)!$customer_group_info['approval'] . "', date_added = NOW()");