Response object in client proxy class is differ from SOAP reponse XML

I'm facing a strange problem: When I add WCF service reference from this site (builded on Java): http://ift.tt/1lruSSz The clien proxy look like this:

public MhubWebServiceProxy.MWS.SubmitMessageResponse MessageSubmission(MhubWebServiceProxy.MWS.Login Login, MhubWebServiceProxy.MWS.SubmitMessageRequest SubmitMessageRequest, byte[] SubmitFile) {
            MhubWebServiceProxy.MWS.MessageSubmissionRequest inValue = new MhubWebServiceProxy.MWS.MessageSubmissionRequest();
            inValue.Login = Login;
            inValue.SubmitMessageRequest = SubmitMessageRequest;
            inValue.SubmitFile = SubmitFile;
            MhubWebServiceProxy.MWS.MessageSubmissionResponse retVal = ((MhubWebServiceProxy.MWS.MessagingHub)(this)).MessageSubmission(inValue);
            return retVal.SubmitMessageResponse;
        }

The response object is SubmitMessageResponse, but when I use Fiddler to capture the response XML, the response look quite differ:

<?xml version="1.0" encoding="utf-8"?>
<SOAP-ENV:Envelope xmlns:SOAP-ENV="http://ift.tt/sVJIaE" xmlns:SOAP-ENC="http://ift.tt/wEYywg" xmlns:xsd="http://ift.tt/tphNwY" xmlns:xsi="http://ift.tt/ra1lAU" xmlns:mhb="http://ift.tt/1lruSSz">
<SOAP-ENV:Body>
<mhb:SubmitResponseMessage>
<mhb:SubmitResponse> <mhb:RequestStatus>0</mhb:RequestStatus> <mhb:MessageId>M201408030115173477752</mhb:MessageId> <mhb:RecipientId>dcst401</mhb:RecipientId> <mhb:SubmissionDate>03082014011517</mhb:SubmissionDate> <mhb:MessageSize>63</mhb:MessageSize> <mhb:DocumentType></mhb:DocumentType> <mhb:NotificationRequestType>N</mhb:NotificationRequestType> <mhb:ContentId></mhb:ContentId> <mhb:Subject></mhb:Subject></mhb:SubmitResponse>
</mhb:SubmitResponseMessage></SOAP-ENV:Body>
</SOAP-ENV:Envelope>

The sequel is, I always get a response as Null in my code. Any body can help ? Regards !