Southern Water false meter readings and an inflated bill

SittingInAChair

I'm wondering if anyone else has had a similar situation.  I received a bill from Southern Water stating that they took a meter reading on 1 September.  The reading they had was quite low considering we used more water than normal that period.  I also didn't recall seeing a Southern Water van at all on the day they took the reading.  With that in mind, I went out to the pavement and read the meter myself.  The actually reading showed that we used almost TWICE the amount of water Southern Water said we used.  Normally, I'd consider this a win, but they had a rate increase of 40% during this period, so any water used in the period should be prorated to the lower rate prior to the price increase.

I contacted Southern Water and they said they'd fix this.  Instead of deleting the false meter reading and re-issuing a bill, they have sent me a bill for 81,000 litres of water used in a three day period!  All of this of course is at the new, higher rate.  I'm fine paying what I owe, but if you do the maths, I'm being asked to pay £46 more than I should be paying, which I have no intention of doing.

Has anyone else gone through something similar with Southern Water?