After the contract ended, and a new supplier took over my electricity, the Coop energy made an enormous estimated final reading and sent it to Affect Energy, who on seeing my own real reading said it can't be true as it was way under a previous Coop estimated reading, from then on over a years nightmare began and still the Coop never sorted it out, in the end I threatened legal action, they then wrote to say they would 'write off' the £89 owing (which I didn't really owe, or not as much in the first place), I though that was the end, then a week later a threatening red letter then another, that was it, I sent another letter saying you'd better inform your legal team I'm taking you to court, two days later they phoned me and apologised! You have been warned!