In message , Set Square
writes
In an earlier contribution to this discussion,
The3rd Earl Of Derby wrote:


It was an estimation, and probably by someone who can't add up, the
correct standing bill will be formalised when he submits his own
reading.

That's not what he said. The start and end of the quarter were *actual*
readings. What was estimated was the reading on the date when the price went
up part-way through the quarter. OP claims (but probably has no direct
evidence) that the actual reading on that date would have been higher than
the estimate - so that more of the quarter's consumption should have been
charged at the old lower price and less at the new higher price.

The fairest way to make an estimate may be pro-rata with number of days -
but that wouldn't really work in the spring when consumption is going down
with time.

Or in this case the autumn quarter, with consumption rising through
October and into November.
TBH, I think the OP's bill was fine, I would expect mid-October-November
consumption to be at least twice that of September-mid-October.

--
steve