Hi all, new to the forum so apologies if I have posted in the wrong place. This is quite a long post as I want to be as thorough as possible, any advice would be appreciated. I moved into my property (2 bed flat, all electric, no gas) in November 2011, shortly after moving in (Feb 2012) I received an electric bill from Npower for around £80/month in electricity. At this point I made a huge effort to lower my usage, to do this I did the following as well as many other things; I reduced my washing machine usage to 2 times a month, I turned off my water heater and used cold water only, I limited showers to 5mins Max on eco setting, I also stopped using all forms of electric heating. Expecting this to drop my bills to around £40 I waited for my next bill, and again the bills where coming through at £80 - £120 a month, at this point I contacted Npower and requested they come inspect my meter. I made the same phone call 3-4 times over the course of 6 months and each time was told my usage was average and they wouldn't investigate, instead threatening to cut me off if I didn't pay my balance immediately. Bringing us to today and my total payments to Npower have been in the region of £3700 - £4000 since November 2011, an average of approx £100/month and somewhere in the region of 9000kwh/year for a 2 bed flat occupied for the last 2years by just myself. Electric consumption is outlined above; one person, working full time, short showers, no heating EVER, no hot water heater and very infrequent use of cooker. Last week whilst doing a meter read I decided to have a quick look at my meter and the cables attached etc, and noticed that my meter is connected to a separate fuse board for the communal lights, sockets, and alarm systems of the flats above me (I'm basement flat with my own door, meter is located in the entry area to the block of flats directly above me). By killing the power to my flat and turning on the lights in the communal areas, and monitoring my meter, I have confirmed that I have been providing the electric for the communal areas since I moved in. I have raised an official complain with Npower and have been told it will be investigated within 10 working days, what I'm wanting to know is, who is responsible for refunding my overpayments? I have been advised by CAB that Npower MUST correct my overpayment first, then persue the landlord for the energy used by the communal areas themselves. Is this the general practice? Or is it possible Npower can just tell me to speak to my landlord to get the money back? Also after speaking to a former tenant of the flats who I knew from his time in the building, he has told me that several of the tenants have been using extension cables from the communal plug sockets (used for cleaning/contractors) to power heaters/appliances in their flats as a way to avoid using their own supply. Whilst this does explain why my usage is so high, how can I prove this is the case when requesting my overpayments back? I can get several tenants to write a statement saying they have witnessed this, but would it be helpful? I'm a little worried Npower are just going to try fob me off with a 10% refund when the real figure I should be refunded is likely to be closer to 70%/80%.. Any help much appreciated, thanks for reading