A Brain Teaser from SWALEC
As I wend my way Brightonwards after a week in Wales, I thought I’d request your assistance in deciphering part of a letter I received from SWALEC, the company that supplies gas and electricity to my Cardiff residence.
If anyone out there can explain the logic that leads from a credit of £163.54 to an increase in my monthly payment – other than the obvious one that SWALEC are trying it on – I’d be most grateful!
In the Dark 
September 8, 2014 at 7:52 pm
The letter states that I am carrying forward a credit of £163.54 because I have used much less electricity in the past year than they expected. This amount is now owed to me.
Let’s set aside the reliability of the “estimate” (which is actually inflated by a factor two) and accept that I will use electricity to the value of £208.05.
The net amount I will owe next year is therefore £208.05-£163.54=£44.51. That is the figure I expected to see in the letter, not the £196.05 that’s actually there and for which I can find no justification.
September 8, 2014 at 8:32 pm
Yes, but you have resorted to traditional mathematical logic here. The SWALEC mathematicians appear to have broken free from the old constraints…
The thing to do would be to contact them via the electric telephone. They will put you on hold long enough for it to start making some kind of sense.
September 9, 2014 at 10:12 am
It’s a genius calculation, no doubt. But your false premise is to believe that they are trying to do a calculation that would put your account in balance. Instead they want to keep your account substantially in credit, so they can help themselves to the interest on your cash, and to protect themselves against future default. As an exercise, you could try and use the information to work out what their target is for how far into credit they want you. Looks to me like it is about 150 pounds credit, which seems to be the position they have already successfully manoeuvred you into and are now trying to preserve.
By contrast your target is to get into debit as far as possible. Maybe you should just cancel the standing order completely and see how long it is before they complain. I can’t see that they would have any basis to do so while your account remains in credit.