When I used Uswitch they didn't want to show results from changing tariff within my existing supplier.
Try and get a quote from EDF directly.
I was formerly with npower and they were fine until a DD problem arose - they increased my electricity DD even though I was in credit and it proved impossible to track down someone to speak to about it.
I am now with EDF - no problems but I suspect they will be the same as npower if a problem does arise.
You are probably right but it seems that npower are notoriously aggressive on how they treat their customer. I was talking to somebody last night who said that last year a newspaper reported a case where npower sent the boys round to collect a gas debt to a house that had not used gas in 10 years. The house owner had replied to their demands by asking to check their records as he did not have a gas meter.
Anyway, I will keep an eye on them and if I find any thing to dispute I'll move to another company, I'm not giving them a second chance. I checked this morning that there are no penalties for leaving the contract early, otherwise I would be looking for another provider instead of typing this post
I just don't get these companies.... the make huge profits already and on top of that they hold excessive amount of cash in credits. 2 or 3 years ago I was with Athlantic and I noticed that we were £640 in credit. I phoned them up to ask why my DD had been put up to £130 for the gas only. They gave me some BS so I moved to EDF.
EDIT:
I've just done a little test on uSwitch

to get tariffs from EDF I pretended that my supplier was already npower and the tariff that I signed for the other day. I entered the usage of gas and electricity and the total estimated expenditure was identical £2600 and pennies. After the search for a better deal the answer it came out with was "
Congratulations, you are on the cheapest plan!
We can remind you when it's time to switch and save.
But we're constantly monitoring the market for cheaper plans.
We can alert you when...."
This was much easier than trying to work out what is what with the information EDF provides
