I''d started by using a sol''s for divorce proceedings but with costs like £13 per phone call made and so on the costs are soon going to spiral as the STBX is going to try and push anything and everything.
Is it as simple as paying the outstanding costs and getting them to send a final instruction that all contact from her sol''s needs to come direct to me??
Write to them and just say you no longer wish for them to represent you, in other words you deinstruct them, also write to court and let them know you are no representing yourself so all documentation is sent directly to you.
You will need to pay the bill, count yourself lucky, calls to solicitors are charged by six minute intervals and often cost £20 per six minutes.
Just so you know wiki offer a respondent fixed price solicitor service for £99, maybe worth thinking about.