DynamicProxyFactory and Azure Service Bus Relay

I'm trying to use DynamicProxyFactory to call a WCF service through the Azure Service Bus Relay (BasicHttpRelayBinding) without service reference.

The problem is that the metadata is not exposed and when I try to create an instance of DynamicProxyFactory, I get the following error.

My question is how can I call a Wcf Service throug HttpRelayBinding without using Service Reference ?

Thanks in advance

factory = new DynamicProxyFactory(uri);

==> throws exception :

System.Exception: An error occured while making the proxy factory :
xxxxx ---> System.InvalidOperationException: Metadata contains a
reference that cannot be resolved : xxxxx --->
System.TimeoutException: The request channel timed out while waiting
for a reply after 00:00:59.9769977. 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.TimeoutException: The HTTP request to
xxxx has exceeded the allotted timeout of 00:01:00. The time allotted
to this operation may have been a portion of a longer timeout. --->
System.Net.WebException: The operation has timed out     at
System.Net.HttpWebRequest.GetResponse()     at
System.ServiceModel.Channels.HttpChannelFactory.HttpRequestChannel.HttpChannelRequest.WaitForReply(TimeSpan timeout)