Disgraceful customer service and billing process! As a result of Npower calculating my bill incorrectly they led me to believe I had credit on my account which I decided to take out of the account to then be told 3 months later that I actually owed them money! Then when I left the company I was not informed how much my final bill was and when it would be taken. Ended up with 7 formal complaints on my account when I left, and was told that I would get money taken off my final bill as a result, but that never ended up happening. Avoid this company at all costs!!!