mblox soap api - php soap Payment Request not working

mblox-soap-api-php-soap-Payment Request不工作，并给出错误。

我在subscribe.php文件中使用如下代码。。。

$client = new SoapClient("https://ngp.us.mblox.com/client-gateway/services?wsdl", array('trace' => 1,  'encoding' => 'UTF-8', 'soap_version' => SOAP_1_2));
$array = array(
'SecurityContext'=>array('userId'=>'aaaaaaaa','password'=>'bbbbbbbb'),
'ClientDetails'=>array('shortcode'=>'234242', 'brandName'=>'aaaaaaaaaa.com', 'programSponsor'=>'aaaaaaaaaa',  'originatingUrl'=>'www.aaaaaaaaaa.com', 'minPageUrl'=>'www.aaaaaaaaaa.com', 'successUrl'=>'www.aaaaaaaaaa.com/subscribConfirm.php', 'cancelUrl'=>'www.aaaaaaaaaa.com', 'tcUrl'=>'www.aaaaaaaaaa.com/terms.html', 'postBackUrl'=>'http://aaaaaaaaaa/subscribe.php'),
'paymentDetails'=>array('paymentType'=>'PSMS', 'amount'=>'9.99', 'currency'=>'USD', 'billingFrequency'=>'MONTHLY'),
'msisdn'=>'243233232',
'serviceId'=>'332',
'operatorId'=>'33343',
'productDescription'=>'Text test',
'optInBody'=>'aaaaaaaaaa',
'browserSessionId'=>'123456',
);
$result = $client->initiatePayment($array);

最后一行显示错误如下=>$result = $client->initiatePayment($array);

致命错误：中的未捕获SoapFault异常：[（null）]/aaaaaaa/Source/development/PHP/ver1/subscribe.PHP：97堆栈跟踪：0/aaaaaaa/Source/development/PHP/ver1/subscribe.PHP（97）：SoapClient->__call（'initiatePayment'，Array）#1/aaaaaaa/Source/development/PHP/ver1/subscribe.PHP（97）：SoapClient->initiatePayment（数组）#2｛main｝已抛出/aaaaaaa/Source/development/PHP/ver1/subscribe.PHP，第97行