awwww I had a similar thing happen to me with British Gas! theyre useless! IN the end I called energywatch who told me they have their own line to British Gas and to call them because when you phone Brit Gas yourself you get the frontline staff who fob you off. I called the number they gave me (dont have now unfortunately or id pass it on) but if you call Energywatch and ask them they should give you the number to call. My probelm was sorted as soon as I said Id contacted Energywatch. I also wrote British Gas a letter of complaint and on the envelope addressed it to the managing director, marking it private and confidential. I received a reply within a week with a cheque for �40 for the inconvenience Id had.
http://www.energywatch.org.uk/
Or you could try contacting the folowing
http://www.thisismoney.co.uk/britishgas
Good Luck, hope you get it sorted soon xx