How could I translate a fault message body in soap12 into a fault message body in soap11?

Hi,I'm able to translate a sop12 message into a soap11 message by 


Message newMessage = Message.CreateMessage(newVersion, oldMessage.Headers.Action, oldMessage.GetReaderAtBodyContents());It works for normal message, but if the oldMessage is a fault message, the client side will throw exception OperationFormatter encountered an invalid Message body. Expected to find node type 'Element' with name 'GetTermKPIs2Response' and namespace 'https://adapi.microsoft.com/Analytics/v1'. Found node type 'Element' with name 's:Fault' and namespace 'http://www.w3.org/2003/05/soap-envelope'



I realize that the saop12 fault message has different body format than soap11. For example,Soap12:                  a:n            ...