I have also spoken to Evan Harris who has said they will respond, but nothing ever happens.
This particular campaign are using a valid grievance (the hacking of phones) as a mechanism to bring in a substantial restraint on the investigation and reporting of issues involving powerful people and the establishment. The least they could do is to answer questions.
Notes: Letter to Chris Jeffries 3rd December 2012 - no response, Email to John Dickinson-Lilley 18th January 2013 - no response, Email to John Dickinson-Lilley 17th March 2013 (no response, but to be fair this is only today). Also an email to the Media Standards Trust Gordon Ramsay 11th February 2013 - no response. (The Media Standards Trust used to be the same as Hacked Off, but now they have been separated).