I wish I could help, I don't know how you can be helped, but if its a consolation this company has now gone under and I still have a pending issue with them myself, where they treated me like a passerby after taking my money and I had to push a 4 year old Toyota Avensis for three months. I had to stop paying in order to get heard. But I think you will need a solicitor. You can try Which Consumer Group for legal advice on
which@which.co.uk or try 0845 307 4000 or 01992 822800. They are very experienced and generally feared by most companies because they have sharp teeth on consumer issues. Their legal department which is made up of independent experienced solicitors, charges just under £10 a month for advice and taking up your case to its logical conclusion.