The Consumer Credit Act has been updated and Rule of 78 doesn't apply to regulated agreements written since 31 May 2005 (GOOD NEWS!!) Instead, they are only entitled to one month's extra interest.

It does still apply to Agreements written before that date (BAD NEWS) It will come into force for these Agreements on 31/5/07 so long as the term is less than 10 years. (GOOD NEWS)

Contact the lender and ask for a settlement figure, and also a quote to refinance that over the remaining term. Then compare their cost with a loan from your bank etc.