Well I first brought this up in April 2016, they told me to provide:

"Information specific to the property, being direct and substantial evidence that an error may have been made when carrying out the original banding (if possible, please submit evidence such as floor plans…)"

Which I sent them - the scanned floorplans and 2015 sale prices for all properties on my development showing that 946sq ft houses were the same band as my 600sq ft flat.

I then re-sent the floorplans in June 2016 and they never got back to me.

Having spoken to them again they have raised another report and the lady on the phone suggested I resend everything.

I should also point out that I told the 2 owners of the only Band C properties that their neighbours in identical houses were on lower bands, but not sure they got anywhere.

Just looking at all the houses and the bands it doesn't make any sense.

How can a 740sq ft 2 bed bungalow be on a higher band than a 946sq ft 3 bed house?

I did think perhaps gardens made a difference, but the lady at the VOA said they don't take them into account.

I also challenged the band at my last rental property - a 1bed in a block of 2 beds - that went through straight away from Band C to Band B, so not sure why I'm not getting anywhere here