Amy Woolfson has written a blog for Disability Rights UK which shows what you can achieve if you are persistent
Amy managed to reduce her sister's council tax bill from £611.20 to £314.08 a year by both challenging the property banding and applying for a reduced bill under the disability reduction scheme.
To view the blog go to http://disabilityrightsuk.blogspot.co.uk/2013/07/you-can-do-it-too-how-amy-managed-to.html