Just keep pestering them! You have finished if they have cancelled the DD. Just wait for the completion letter.
Sharing from experiences of dealing with debt
The greatness of a man is not in how much wealth he acquires, but in his integrity and his ability to affect those around him positively.
Bob Marley. http://kallis3.blogs.iva.co.uk
Louise, it is pretty much standard for your IP to lose interest in you once you have come to the end -- they all seem to go silent between that last payment and the issue of the completion certificate, which could, as previously advised, be up to 6 months.
My opinions are merely that .. opinions based on experience. Always seek professional advice.
IVA Completed 23rd July 2013 .... C.C. 10th January 2014