SOAP encoding problem

Hi, I have a problem when send a request to a WebService that receive 
messages in this format:

<?xml version="1.0" encoding="utf-8"?>
<soap:Envelope xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/">
  <soap:Body>
    <StartTransaction xmlns="http://www.MySite.com">
     <Param1>string</Param1>
     <Param2>string</Param2>
     <Param3>int</Param3>
    </StartTransaction>
  </soap:Body>
</soap:Envelope>


But when I build and send the request using SOAP, it send something like 
this:

<<?xml version="1.0" encoding="UTF-8" ?>
<SOAP-ENV:Envelope 
xmlns:SOAP-ENV="http://schemas.xmlsoap.org/soap/envelope*/*" 
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
xmlns:xsd="http://www.w3.org/2001/XMLSchema">
    <SOAP-ENV:Body>
         <ns1:StartTransaction xmlns:ns1="http://www.MySite.com*/*" 
SOAP-ENV:encodingStyle="http://schemas.xmlsoap.org/soap/encoding*/*">
            <Param1 xsi:type="xsd:string">value1</Param1>
             <Param1 xsi:type="xsd:string">value12</Param1>
             <Param1 xsi:type="xsd:int">1</Param1>
            </ns1:StartTransaction>
          </SOAP-ENV:Body>
    </SOAP-ENV:Envelope>


And I got this Exception message: No Deserializer found to deserialize a 
'http://www.MySitecom:StartTransactionResult' using encoding style 'null'.

This is the code that I'm using:

         Call call = new Call();
       
        call.setEncodingStyleURI(Constants.NS_URI_SOAP_ENC);
              
        call.setTargetObjectURI("http://www.MySite.com/");
        call.setMethodName("StartTransaction");

        //  I set parameters encoding to null


*As you can see, the namespaces that SOAP build are distinct to the 
namespaces that I need send the request (see WebService format message), 
I think that could be the problem.
But I don't know how to change them.
*


*Any help will be very appreciated.*

*Thanks.*