I don't know if my situation will help you see some light at the end of the tunnel but i am going through financial difficulty at the moment and have a £440 (plus £110) interest with payday express, have had it deferring over a few months and i phoned them before Christmas to advise them of this, as i am sick of paying interest and nothing else. I was passed from pillar to post and had my account on hold for 2 weeks. They took £45 late payment fees from my account today and I spoke to a few people then a manager phoned me back quite a few hours later. He told me my account was now £660 as more interest had been added. He credited the £110 and also put the £45 back in my bank account and agreed a payment plan with me for £10.00 per week with no extra interest.
Keep at them...they will give in! I have received my credit agreement via email