Java Programming

Dear Java EE Experts,
I have developed a JAX-WS based web service client in net beans. The WSDL is successfully imported. I can create objects based on classes gernerated from WSDL. But when I call the actual web service method (giving an input object and expecting a return/output object), I get an exception:
===============================
Exception in thread "main" com.sun.xml.internal.ws.client.ClientTransportException: The server sent HTTP status code 400: Bad Request
at com.sun.xml.internal.ws.transport.http.client.HttpTransportPipe.checkStatusCode(HttpTransportPipe.java:196)
at com.sun.xml.internal.ws.transport.http.client.HttpTransportPipe.process(HttpTransportPipe.java:168)
at com.sun.xml.internal.ws.transport.http.client.HttpTransportPipe.processRequest(HttpTransportPipe.java:83)
at com.sun.xml.internal.ws.transport.DeferredTransportPipe.processRequest(DeferredTransportPipe.java:105)
at com.sun.xml.internal.ws.api.pipe.Fiber.__doRun(Fiber.java:587)
at com.sun.xml.internal.ws.api.pipe.Fiber._doRun(Fiber.java:546)
at com.sun.xml.internal.ws.api.pipe.Fiber.doRun(Fiber.java:531)
at com.sun.xml.internal.ws.api.pipe.Fiber.runSync(Fiber.java:428)
at com.sun.xml.internal.ws.client.Stub.process(Stub.java:211)
at com.sun.xml.internal.ws.client.sei.SEIStub.doProcess(SEIStub.java:124)
at com.sun.xml.internal.ws.client.sei.SyncMethodHandler.invoke(SyncMethodHandler.java:9Cool
at com.sun.xml.internal.ws.client.sei.SyncMethodHandler.invoke(SyncMethodHandler.java:7Cool
at com.sun.xml.internal.ws.client.sei.SEIStub.invoke(SEIStub.java:107)
at $Proxy28.smsSpcIPCC(Unknown Source)
at javaapplication1.Main.smsSpcIPCC(Main.java:34)
at javaapplication1.Main.recordComplaint(Main.java:54)
at javaapplication1.Main.main(Main.java:25)
Java Result: 1
BUILD SUCCESSFUL (total time: 2 minutes 22 seconds)
===============================

The code snippet that causes the runtime exception is (exception comes on last line of this code:
===============================
ServiceRequest sr = new ServiceRequest();
sr.setSerialNumber("211778");
sr.setProductCode("PSTN");
sr.setMSISDN("03005499257");
sr.setComplaintType("P1");
sr.setStatus("Open");
sr.setSubStatus("Unassigned");

com.siebel.customui.SMSSpcIPCCInput input = new SMSSpcIPCCInput();
input.setOperation("Registration");

ListOfWcServiceRequestIo srList = new ListOfWcServiceRequestIo();
srList.getServiceRequest().add(sr);
input.setListOfWcServiceRequestIo(srList);

SMSSpcIPCCOutput output = smsSpcIPCC(input);
===============================

Not sure how to resolve it. Please help.

Thanks & Regards,
Ahsan