It is not true when they tell you they can not offer you another agreement. I have had several 6 months agreements with them, all with no interest being charged.
Contact
http://www.nationalde...country=england_wales
They offer great free impartial advice and there are lots of draft letters you can use, helps you work out exactly where you are financially and what you can afford. Fill out a personal budget plan and send this to them. Don't listen to people lecturing you on how you got into to debt it is none of their business, you are and you want to deal with rather than ignore/avoid it.
Good luck to you.