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.