Here's the automated response to my filling in a response form on npower's website [they keep sending me the bill for something that I paid for six months ago].
Can you believe it - 7 to 10 days to respond? That's up to two weeks on their Mon-Fri working times. To paraphrase what I said back in 2008:
Yep, they can supply folk to answer phones 12 hours a day, but it can take 10 days to answer an email!