Port Name change after undeploy/deploy

We had a service deployed to our production mediator environment, in which we were seeing the port name of the virtual service being picked up from the native service. Thus, the port name was something like ‘ServicePort’. We wanted to hook up an additional run time policy to this service, for which we followed these steps:

  1. Create run time policy and add scope based on description.
  2. Edit the description of the virtual service so that the policy gets applicable to it.
  3. Undeploy the virtual service.
  4. Deploy the virtual service.

After following the above steps, when we see the WSDL file, the port name in the WSDL has changed to something generated by the mediator “vServicesoaphttpsBillingServiceBinding_pep” where pep is the name of the target defined in CentraSIte. The clients have been configured based on the old port name, and hence they are currenly unable to invoke the service.
Please note: We are seeing the same changed port name in the registry WSDL of the virtual service as well.
Why has the port name changed ? and how can this be undone ?

CS v8.0