I don't know, but if £68 is your cash to feed the family for a week, or do this, I'd say buy the food.
On the other hand, of you've got a bad credit rating and £68 to spend doing this or going to the pub...
I would check them out as well as you can - I've just found this on google, with apologies to Moneysupermarket if this goes against terms of use
www.thisismoney.co.uk/consumer/article.html?in_article_id=387123&in_page_id=5&in_a_source=
which suggests that they can fix errors, but not correct entries.