I have never changed utility suppliers and tbh after looking at the switching sites I'm not bowled over by the savings - british gas offering a derisory £14 per year dual fuel discount for example! Anyway we are recommended edf and I wondered whether they were rated or not for customer service - and is there anything to watch out for, like getting locked into a contract? One reason savings are disappointing is that I insist on paper bills and quarterly bills - I don't like monthly direct debit as I would rather just pay for what I have used.
EDF were awfull. It took at least a dozen phonecalls and 4 letters to get them to stop sending me threatening (and incorrect) bills. I resorted to sending the appropriate evidence in triplicate by recorded delivery. It took over a year to sort the problem out. Never, never again.
I am with edf, on prepayment. When I lost my electric key I rang up at 9.10 and the bloke sorted it out there and then on the phone, and arranged for me to pick up a new key from a shop down the road for 10 oclock, I just needed to give them a password. Perfect service.
They've been competent with me, although I've just switched to E-on for both gas and leccy with some big introductory discount - I get to pay quarterly but bills are online (used moneysupermarket.com)
I don't trust any of them with direct debit. Although ended up with a year free gas once after Npower told us actually they hadn't been supplying us after all and wouldn't take our money - London Electric tried to get me to pay but I pointed out I had no contract with them!