CF are notorious for bad communication, as well as telling debtors several versions of the truth as it suits them !
They are, however, sort of correct in their response to you failing the IVA. In all IVAs it is generally agreed that fees come out first and it is usually a couple of years before creditors actually get anything back. This is compounded by CF charging higher fees than most.
In any IVA, with any company, though, if the arrangement fails, the creditors will add back lost contractual interest, which, in most cases, will more than swallow any payments the debtor has made in the meantime, so most of us would find ourselves back at square one, owing a little more than we started with, as well as having less than happy creditors to now deal with. To say nothing of having flushed away the last few years.
I am afraid that the best you can do is wait it out, if at all possible. If you still feel the (understandable) need to 'get heavy' threaten to complain to their regulatory body, which, if found against them, could result in a hefty fine --- better to hit their pockets than yours. However, CF strike me as the type to use punitive measures !
My opinions are merely that .. opinions based on experience. Always seek professional advice.
IVA Completed 23rd July 2013 .... C.C. 10th January 2014