Exception Handling Helper
One thing which I noticed is this little spelling error in the code  


static IExeptionHandlerProvider _exeptionHandlerProvider = null;  



Both the name of the interface and the name of the field should be fixed by adding a c -> IExceptionHandlerProvider _exceptionHandlerProvider = null;



public static void HandleException(FaultException&lt;DefaultFaultContract&gt; fault)  

You should initialze the StringBuilder's with a starting capacity, because the default capacity of a StringBuilder is 16 characters, and if it is reached the capacity will be doubled which involves copying the current buffer to the newly created buffer. 

By choosing the initial capacity to be e.g 256 you will maybe waste some memory but you avoid the internal increasing of the buffer.