If you continue to get no answer , telephone the Law Society in Chancery Lane, London. This is the governing body of solicitors. Tell them that you are a lay person who may have a complaint about a solicitor and ask them to connect you to someone to give advice about proper professional practice. They will refer you to the relevant department, which, I think, is out in the countryside somewhere now.
A solicitor is not allowed to sit on funds, nor to fail to give a proper account of such transactions as this.This one may be breaking professional rules but, in any case, a call from the Law Society will most certainly ginger them up !