I knew the gas companies got up to some dodgy tricks - a while ago my gas bill was so far out (over estimated) that I gave them a corrected reading. For some reason (possibly my fault), initially the reading they got was even worse (extra 1000GBP to pay). When I got this bill, all the extra gas had been charged at the most recent (highest) rate. When I then gave them the correct reading and the recalculated again, they went back and redid all the estimates across the year - so that I had more usage in the higher rates than I would have done if they'd just adjusted my final bill (to be negative). I accept the recalculating was fair (infact they had to recalculate at least one previous bill otherwise my usage would have been negative for a quarter), but it should also have been done for the bill where it appeared I'd been underestimated.
I notice that the BBC has something about people having huge debts because of underestimated bills - I wonder how prevalent this effect is. With prices rising, it makes sense to underestimate your customers usage and then bill them at the highest rate.
But I've just found an even more egarious fraud. Because of the above, I've started always giving a correct reading every time I get an estimated bill.
I got an estimated bill with an estimated reading of 5596 dated 11th Jan. I sent in the correct reading of 5687 (which I will have read on the day I got the bill) and got a new bill dated 16th Jan (So I must have read it some time between 11th and 16th Jan). I've just been updating my spreadsheet of gas usage, and I noticed that my (final) bill of 5th May has two prices. The gas price changed on 18th Jan[1], but rather than work from my (pre) 16th Jan actual reading, they've gone back to the 11th Jan estimate and then estimated the 18th Jan value as
5629 which is clearly too low. This makes a difference of 1.55 (plus VAT) or about and extra 3% on my bill.
(I'm no longer with EDF - we'll see how things go with a different supplier)
I'd started always checking the readings of my bill and giving corrected readings, but I'd never thought to check that they were using the correct value from the previous bill. I've got another bill where the original bill was for the period 18th July to 11th Oct, but the corrected bill is for 28th Jun to 15th Oct. I have, so far, been unable to work out whether they've charged me double for the period 28th June to 18th July due to the bizarre way they calculate their bills (I think they are correct and haven't double charged me but it depends on some complex calculations on partial bits of the 13th April to 18th July bill to be sure)
So, it isn't sufficient to check that the meter reading on your bill matches the meter, you also need to go back to previous bills and make sure there's been no shenanigans there either :-( And the calculations aren't easy when your bill periods overlap and they "refund" part of the previous bill before recalculating your current bill from an intermediate date in a previous bill.
Tim.
[1] If I'd understood how this switching malarky worked I'd not have had to pay the higher price at all but I didn't understand all the hoops I had to jump though to get my price fixed while the switch was taking place - I actually started the switching process as soon as the price increase was announced in the news, and before it actually took place.