You will need to give them a call - it could be that a creditor has not put in a claim yet.
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
It is probably the balance they hold on the account, which is yet to be dealt with by setting it against fees, disbursements and remaining creditor claims.
My opinions are merely that .. opinions based on experience. Always seek professional advice.
IVA Completed 23rd July 2013 .... C.C. 10th January 2014