.NET Web Service (asmx) Timeout Problem

I'm connecting to a vendor-supplied web ASMX service and sending a set of data over the wire. My first attempt hit the 1 minute timeout that Visual Studio throws in by default in the app.config file when you add a service reference to a project. I increased it to 10 minutes, another timeout. 1 hour, another timeout:

Error: System.TimeoutException: The request channel timed out while waiting for
a reply after 00:59:59.6874880. Increase the timeout value passed to the call to
 Request or increase the SendTimeout value on the Binding. The time allotted to
this operation may have been a portion of a longer timeout. ---> System.TimeoutE
xception: The HTTP request to 'http://servername/servicename.asmx' has exceeded the allotted timeout of 01:00:00. The time allotted to this
operation may have been a portion of a longer timeout. ---> System.Net.WebExcept
ion: The operation has timed out
   at System.Net.HttpWebRequest.GetResponse() [... lengthly stacktrace follows]

I contacted the vendor. They confirmed the call may take over an hour (don't ask, they are the bane of my existence.) I increased the timeout to 10 hours to be on the safe side. However the web service call continues to time out at 1 hour. The relevant app.config section now looks like this:

   <basicHttpBinding>
    <binding name="BindingName" closeTimeout="10:00:00"
                    openTimeout="10:00:00" receiveTimeout="10:00:00" sendTimeout="10:00:00"
                    allowCookies="false" bypassProxyOnLocal="false" hostNameComparisonMode="StrongWildcard"
                    maxBufferSize="2147483647" maxBufferPoolSize="524288" maxReceivedMessageSize="2147483647"
                    messageEncoding="Text" textEncoding="utf-8" transferMode="Buffered"
                    useDefaultWebProxy="true">
     <readerQuotas maxDepth="32" maxStringContentLength="8192" maxArrayLength="2147483647"
                        maxBytesPerRead="4096" maxNameTableCharCount="16384" />
     <security mode="None">
      <transport clientCredentialType="None" proxyCredentialType="None" realm="" />
      <message clientCredentialType="UserName" algorithmSuite="Default" />
     </security>
    </binding>
   </basicHttpBinding>

Pretty absurd, but regardless the timeout is still kicking in at 1 hour. Unfortunately every change takes at least an additional hour to test. Is there some internal limit that I'm bumping into - another timeout setting to be changed somewhere? All changes to these settings up to one hour had the expected effect.

Thanks for any help you can provide!

Firstly: See Steven Cheng[MSFT] response here about timeouts. There is a execution timeout you can set for httpRuntime. He says something interesting after that, which is "Also, make sure that you've set the 'compilation debug="false"' as to make the timeout work correctly"

Besides the fact that something may be terribly wrong on their end (or the data returned is so voluminous/ I'm not going to judge - might be a good reason), have you tried calling their operation Asynchronously? Same results? I guess it would take an hour

YourVendor.WebService ws = new YourVendor.WebService();
ws.LongRunningOperationCompleted += new YourVendor.LongRunningOperationEventHandler(ws_LongRunningOperationCompleted);

ws.LongRunningOperationAsync();

// Implement the ws_LongRunningOperationCompleted handler (stub will auto generate)

The completed event handler will have a specific event args param, which will contain the results, for event args e, e.Result should have what you need when it completes.