Safe DbContext Disposal
You shouldn't need to call Dispose and new up another context in the Save method. SaveChanges should be good enough.  I would recommend you make ClientService IDisposable and when that class disposes then dispose of the context as well.

Update from comment

to implement IDisposable on the IClientService 

public interface IClientService : IDisposable


The will now require a Dispose method on any class that implements IClientService.  In the dispose method you should call the dispose method of the context.