Thanks for your enquiry.
All Solicitors are under a duty to act efficiently and to observe client care. If a client is unhappy with the service being provided, a client has the right to complain. All Solicitors must have a "Complaints procedure" and all clients are entitled to request the details of this procedure.
Like everyone, no Solicitors like to receive complaints, especially as the client does have a right to also complain to the Solicitors Regulation Authority (SRA) if they are not satisfied with the service being given, once the Solicitors Complaints procedure has been followed.
I would therefore suggest that your friend emails or writes to his Solicitor expressing his dissatisfaction and stating that unless the service improves, he will be asking for the Firm's Complaints procedure. I would hope this then does the trick. Alternatively, if it has got so bad, your friend may want to email or write straight away, asking for the Complaints procedure. If the service does not then improve, your friend should contact the SRA (DETAILS HERE--http://www.sra.org.uk/consumers/problems/report-solicitor.page
I hope this assists and sets out the legal position.