Just in case anyone is interested.....
I checked my council tax banding on here www.voa.gov.uk/council_tax/cti_home.htm
and looked at all my neighbours too. Discovered that we were on the same or higher banding as lots of our neighbours in much bigger houses. So... I complained. Got a letter the other day saying very sorry, they've changed our banding. No sign of any cheque so I phoned up and was promised that the council ahve to repay all over payments back till the date we moved into our house!! Wayhay!! August 2000! Got a leter from the council detail overpayments at about £1400 but almost £400 will be taken off our current bill and the rest will be sent out in a cheque! Woohhoooo!! My CT bill for the next 3 months is £30!
Worth a go!