Consume wcf Error

Hi Alls,
I have to consume an external wcf service (developed by some other party). When I browse it (eg : https://testservice.test1.com/calculate.svc), it give me the following mesage;
Metadata publishing for this service is currently disabled.
If you have access to the service, you can enable metadata publishing by completing the following steps to modify your web or applica ---------
When I try to add this service in my web application by right clicking in the solution explorer, Add Service Reference, its not allowing to add.
Please help me;