lilac,
I really suggest you raise a complaint, lifenotsoseasy has done a great post here about this:
in this thread:
http://www.iva.co.uk/forum/topic.asp?TO ... hichpage=1 at 09:37 on the 30th August.
I think your first step is to write to them explicity asking them to identify the terms of the agreement that allow them to insist on secured loan avenue. (in writing). In the meantime follow lifenotsoeasy post guide, then you know exactly where you stand. armed with that information you can make an informed decision.
Also for reference unless the terms and implications of something were not made very clear to you when it comes to financially related stuff it is possible they will have breached FSA regulations regarding miss-sellling.
I would pop and see the Citizens advice burea, maybe also a free half hour with a solicitor.
There is something called Unfair terms in Consumer contracts, and you cant be held to something if it was not clear what the implications would have been and also the angle if they did not insisit you got advice before signing them (if you have), I don't know if they would apply in such a case if such a firm didn't make it clear what the implications would be of changing your terms, again a solicitor or CAB might be able to help.
https://www.citizensadvice.org.uk/consu ... contracts/
If it was me, the last thing I would do is, just agree and do it, find out where you actually stand by asking them to explicitly provide the details of agreement hat allow this and then move forward (in my unprofessional personal opinion).