Able to contact C# web service from C# applciation but not powershell

Hi All,

I've been trawling the web but can only find detailed information on how to use powershell from C# but not the other way round.

Basically i have a web service that imports or removes a machine from SCCM collections. My code that calls it from C# is below (it is pretty simple):

ServerWebService.ServiceClient sc = new ServerWebService.ServiceClient();
errorMessage = sc.AddComputer(computerName, macAddress, collectionName, siteCode);
//errorMessage = sc.RemoveComputer(computerName, collectionName, siteCode);
Console.WriteLine(errorMessage);

The web service will return an error message or a success message which is then written to the console - this works fine.

However if i send the same information to the same web service using the below code:

$wbsvce = New-WebServiceProxy -Uri http://SERVERNAME/AddRemCompWebService/Service.svc?wsdl
$returnMessage = $wbsvce.AddComputer($ComputerName,$MacAddress,$CollectionName,$SiteCode)
Write-Output $returnMessage

I get a timeout error as seen below:

Exception call "AddComputer" with "4" argument(s): "The operation timed out"
At "POWERSHELLFILELOCATION"+ $returnmessage = $websvce.AddComputer($ComputerName,$MacAddress,$CollectionName,$SiteCode)+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~+ CategoryInfo          : NotSpecified: (:) [], MethodInvocationException+ FullyQualifiedErrorID : WebException

Is there anything that needs to be included in the C# web service to accept requests from powershell scripts?
I understand that this is timing out but why? I am essentially running the same code as the C# way of calling the web service?

I look forward to your replies! Thank you.