Ok, you're using  my $result = $soap->Payment(@data); but you're expecting the xml to say PaymentRequestMsg, well you have to use ->PaymentRequestMsg for that to happen

Does that get you closer?

#!/usr/bin/perl --
use strict;
use warnings;
use SOAP::Lite  +trace => 'debug', readable => 1;
my $soap = SOAP::Lite
    -> uri('http://127.0.0.1/MyModule')
    -> proxy('http://127.0.0.1:1203')
;;;;;;;;;
$soap->ns( "http://www.huawei.com/bme/cbsinterface/common" => 'ns1' );
$soap->ns( "http://www.huawei.com/bme/cbsinterface/cbs/accountmgr" => 
+'ns2' );
$soap->ns( "http://www.huawei.com/bme/cbsinterface/cbs/accountmgrmsg" 
+ => 'ns3',);
$soap->envprefix('SOAP-ENV');
my @data = SOAP::Data->name("RequestHeader" =>
  \SOAP::Data->value(
   SOAP::Data->name("CommandId" => 'Payment')->prefix('ns1'),
   SOAP::Data->name("Version" => '1')->prefix('ns1'),
   SOAP::Data->name("TransactionId" => '')->prefix('ns1'),
   SOAP::Data->name("SequenceId" => '1')->prefix('ns1'),
   SOAP::Data->name("RequestType" => 'Event')->prefix('ns1'),
   SOAP::Data->name("SerialNo" => 'USSD_00000001')->prefix('ns1'),
   )
);
push (@data,
   SOAP::Data->name("PaymentRequest" =>
  \SOAP::Data->value(
   SOAP::Data->name("SubscriberNo" => '123')->prefix('ns2'),
   SOAP::Data->name("PaymentAmt" => 100)->prefix('ns2'),
   SOAP::Data->name("PaymentMode" => 1001)->prefix('ns2'),
   )
));

my $result = $soap->PaymentRequestMsg(@data);
__END__

$ perl soap-lite-1145282.pl
SOAP::Transport::HTTP::Client::send_receive: POST http://127.0.0.1:120
+3 HTTP/1.1
Accept: text/xml
Accept: multipart/*
Accept: application/soap
Content-Length: 1380
Content-Type: text/xml; charset=utf-8
SOAPAction: "http://www.huawei.com/bme/cbsinterface/cbs/accountmgrmsg#
+PaymentRequestMsg"

<?xml version="1.0" encoding="UTF-8"?>
<SOAP-ENV:Envelope
    SOAP-ENV:encodingStyle="http://schemas.xmlsoap.org/soap/encoding/"
    xmlns:SOAP-ENV="http://schemas.xmlsoap.org/soap/envelope/"
    xmlns:ns1="http://www.huawei.com/bme/cbsinterface/common"
    xmlns:ns2="http://www.huawei.com/bme/cbsinterface/cbs/accountmgr"
    xmlns:ns3="http://www.huawei.com/bme/cbsinterface/cbs/accountmgrms
+g"
    xmlns:soapenc="http://schemas.xmlsoap.org/soap/encoding/"
    xmlns:xsd="http://www.w3.org/2001/XMLSchema"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
  <SOAP-ENV:Body>
    <ns3:PaymentRequestMsg>
      <RequestHeader>
        <ns1:CommandId xsi:type="xsd:string">Payment</ns1:CommandId>

        <ns1:Version xsi:type="xsd:int">1</ns1:Version>

        <ns1:TransactionId xsi:type="xsd:string" />

        <ns1:SequenceId xsi:type="xsd:int">1</ns1:SequenceId>

        <ns1:RequestType xsi:type="xsd:string">Event</ns1:RequestType>

        <ns1:SerialNo xsi:type="xsd:string">USSD_00000001</ns1:SerialN
+o>
      </RequestHeader>

      <PaymentRequest>
        <ns2:SubscriberNo xsi:type="xsd:int">123</ns2:SubscriberNo>

        <ns2:PaymentAmt xsi:type="xsd:int">100</ns2:PaymentAmt>

        <ns2:PaymentMode xsi:type="xsd:int">1001</ns2:PaymentMode>
      </PaymentRequest>
    </ns3:PaymentRequestMsg>
  </SOAP-ENV:Body>
</SOAP-ENV:Envelope>
SOAP::Transport::HTTP::Client::send_receive: 500 Can't connect to 127.
+0.0.1:1203
Content-Type: text/plain
Client-Date: Tue, 20 Oct 2015 01:56:11 GMT
Client-Warning: Internal response

Can't connect to 127.0.0.1:1203

No connection could be made because the target machine actively refuse
+d it. at .../site/lib/LWP/Protocol/http.pm line 47.
500 Can't connect to 127.0.0.1:1203 at soap-lite-1145282.pl line 40.
[download]

I tried that just now, my current code is:

#!/usr/bin/perl --
use strict;
use warnings;
use SOAP::Lite  +trace => 'debug', readable => 1;

my $soap = SOAP::Lite-> service('http://10.230.0.22:7782/services/CBSI
+nterfaceAccountMgrService?wsdl');

$soap->ns("http://www.huawei.com/bme/cbsinterface/common" => 'ns1');
$soap->ns("http://www.huawei.com/bme/cbsinterface/cbs/accountmgr" => '
+ns2');
$soap->ns("http://www.huawei.com/bme/cbsinterface/cbs/accountmgrmsg" =
+> 'ns3');
$soap->envprefix('SOAP-ENV');
my @data = SOAP::Data->name("RequestHeader" =>
  \SOAP::Data->value(
   SOAP::Data->name("CommandId" => 'Payment')->prefix('ns1'),
   SOAP::Data->name("Version" => '1')->prefix('ns1'),
   SOAP::Data->name("TransactionId" => '')->prefix('ns1'),
   SOAP::Data->name("SequenceId" => '1')->prefix('ns1'),
   SOAP::Data->name("RequestType" => 'Event')->prefix('ns1'),
   SOAP::Data->name("SerialNo" => 'USSD_00000001')->prefix('ns1'),
   )
);
push (@data,
   SOAP::Data->name("PaymentRequestMsg" =>
  \SOAP::Data->value(
   SOAP::Data->name("SubscriberNo" => '123')->prefix('ns2'),
   SOAP::Data->name("PaymentAmt" => 100)->prefix('ns2'),
   SOAP::Data->name("PaymentMode" => 1001)->prefix('ns2'),
   )
));

my $result = $soap->Payment(@data)
[download]

However none of the settings are reflected in the output

SOAP::Transport::HTTP::Client::send_receive: POST http://10.230.0.22:7
+782//services/CBSInterfaceAccountMgrService HTTP/1.1
Accept: text/xml
Accept: multipart/*
Accept: application/soap
Content-Length: 1075
Content-Type: text/xml; charset=utf-8
SOAPAction: "Payment"

<?xml version="1.0" encoding="UTF-8"?><SOAP-ENV:Envelope SOAP-ENV:enco
+dingStyle="http://schemas.xmlsoap.org/soap/encoding/" xmlns:SOAP-ENV=
+"http://schemas.xmlsoap.org/soap/envelope/" xmlns:account="http://www
+.huawei.com/bme/cbsinterface/cbs/accountmgr" xmlns:accountmgrmsg="htt
+p://www.huawei.com/bme/cbsinterface/cbs/accountmgrmsg" xmlns:common="
+http://www.huawei.com/bme/cbsinterface/common" xmlns:http="http://sch
+emas.xmlsoap.org/wsdl/http/" xmlns:mime="http://schemas.xmlsoap.org/w
+sdl/mime/" xmlns:soap="http://schemas.xmlsoap.org/wsdl/soap/" xmlns:s
+oap12="http://schemas.xmlsoap.org/wsdl/soap12/" xmlns:soapenc="http:/
+/schemas.xmlsoap.org/soap/encoding/" xmlns:wsaw="http://www.w3.org/20
+06/05/addressing/wsdl" xmlns:wsdl="http://schemas.xmlsoap.org/wsdl/" 
+xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.
+org/2001/XMLSchema-instance"><SOAP-ENV:Body><account:Payment><Request
+Header xsi:nil="true" xsi:type="common:RequestHeader" /><PaymentReque
+st xsi:nil="true" xsi:type="account:PaymentRequest" /></account:Payme
+nt></SOAP-ENV:Body></SOAP-ENV:Envelope>
SOAP::Transport::HTTP::Client::send_receive: HTTP/1.1 500 Internal Ser
+ver Error
Connection: close
Date: Tue, 20 Oct 2015 06:46:42 GMT
Server: Apache-Coyote/1.1
Content-Type: text/xml;charset=utf-8
Client-Date: Tue, 20 Oct 2015 06:44:52 GMT
Client-Peer: 10.230.0.22:7782
Client-Response-Num: 1
Set-Cookie: JSESSIONID=9B4FC1D1F720D25705C2CC7FC46B9616.server1; Path=
+/
X-Powered-By: Servlet 2.4; JBoss-4.0.5.GA (build: CVSTag=Branch_4_0 da
+te=200610162339)/Tomcat-5.5
X-UA-Compatible: IE=EmulateIE7

<?xml version='1.0' encoding='utf-8'?><soapenv:Envelope xmlns:soapenv=
+"http://schemas.xmlsoap.org/soap/envelope/"><soapenv:Header /><soapen
+v:Body><soapenv:Fault><faultcode>soapenv:Client</faultcode><faultstri
+ng>Data binding error</faultstring><detail /></soapenv:Fault></soapen
+v:Body></soapenv:Envelope>
[download]