yii2 try cactch没有捕获异常，为什么呢，谢谢 [ 2.0 版本 ]

/**
* 获得银行卡
* @param array $data
* @return string
*/
public function getBank($data) {
    try {
        $client = $this->getClient();
        $params = $this->getConnectParams(array('username' => $data['username']));
        $response = $client->GetBank($params);
        $return_json = $response->GetBankResult;
        $return_arr = json_decode($return_json) ;
        $status = $return_arr->result ;
    } catch (Exception $e) {
        self::addLog($e);
        $status = 'error';
    }
}

程序直接在GetBank处报错，没有捕获到异常，

SoapFault
Function ("GetBank") is not a valid method for this service