Do not even consider using this company - Untrustworthy liars.
I decided to migrate from Npower to another supplier in December 2012 and 5 months later they still have not been able to resolve and issue the credit refund whch I am owed. Was on their dual fuel scheme and back in January received a final gas bill showing over £400 in credit, 2 days later a `for information only` statement showing £223.01. Contacted them and told allow 30 days for refund. No final electric bill arrived nor refund so contacted them again. Told it would be sorted within 10 days which it wasnt so completed their online complaints form which, other than their auto response` email was completely ignored. Loads more phone calls to them and I finally thought I was getting somewhere on 4th May after spending 1h 40 mins going through everything again. Supposedly she had found, sorted the problem,finalised my account and authorized the refund and informed me this would be in my account within 3-5 working days. Needless to say the refund has not appeared up to today..
Do not believe a word this company says. In my opinion their whole operation should be fully investigated by the Energy Ombudsman.