calling a soap service from C#

I have working PHP code which calls a SOAP service and it works. Its as follows:

<?php
try
{
    $client = new SoapClient(null, array(
        'location' => "http://108-168-196-91.mycitrixdemo.net/zdm/services/EveryWanDevice?wsdl",
        'uri' => "http://zdemo2.zenprise.com",
        'login' => "Admin",
        'password'=> "XXXXX"));

    $properties=$client->getDeviceProperties("XXXXXXXX",null);

    for($i=0;$i<count($properties);$i++) {
        printf ("name: %s, value: %s\n" , $properties[$i]->name, $properties[$i]->value);
    }
}
catch (Exception $e)
{
    print_r($e); exit;
}
?>

I need to access the same service from C#. I have tried adding Service Reference to http://108-168-196-91.mycitrixdemo.net/zdm/services/EveryWanDevice?wsdl and this added the following section in my app.config.

<system.serviceModel>
    <bindings>
        <basicHttpBinding>
            <binding name="EveryWanDeviceSoapBinding" />
        </basicHttpBinding>
    </bindings>
    <client>
        <endpoint address="http://108-168-196-91.mycitrixdemo.net/zdm/services/EveryWanDevice"
            binding="basicHttpBinding" bindingConfiguration="EveryWanDeviceSoapBinding"
            contract="ServiceReference1.DeviceService" name="EveryWanDevice" />
    </client>
</system.serviceModel>

I am now provided with the proxy classes but I dont know how to set them up so I could call this service.

I am doing it as follows in C#:

DeviceService srv = new DeviceServiceClient();//
srv.authenticateUser(new authenticateUserRequest("Admin", "XXXXXX"));

var devices = srv.getDeviceProperties(new getDevicePropertiesRequest("99000067296308", null));

But the srv.authenticateUser line throws the following exception:

RPC Message getDeploymentHistoRequest1 in operation getDeploymentHisto1 has an invalid body name getDeploymentHisto. It must be getDeploymentHisto1

I have no idea what does this error mean. Can anybody help?