Hi Alex,
http://www.oxfordaviation.net/company/distance.htm
I'll think I'd better apologise.
When I took a "quick" look at the news article on the Oxford website main page, one of the key points it makes is "FREE attendance at revision sessions" but my eyes didn't read the "if you fail a subject" and further I didn't even click on the "more information link".
Yup you're right, on par with other schools as you're paying for each brush up course individually, sorry for jumping the gun!
Best wishes,
Charlie Zulu.