I've been with Octopus for a few years now -- think they're very good. For example, I'd built up a load of credit, emailed them last weekend and they'd refunded me by Wednesday. (They do leave a bit of the excess credit in as a buffer but they're very clear about that and I believe you can change your DD amount quite easily.)
Oh, and when I first switched to them, they were proposing a DD that was higher than I'd been paying (apparently they base it on a standard three bed house or something). I contacted them, told them what I had been paying and they adjusted it downwards with no hassle at all and said if I got back to them after a few months and did some meter readings, they could adjust as necessary.
Oh, and when I first switched to them, they were proposing a DD that was higher than I'd been paying (apparently they base it on a standard three bed house or something). I contacted them, told them what I had been paying and they adjusted it downwards with no hassle at all and said if I got back to them after a few months and did some meter readings, they could adjust as necessary.