Hi! I was a happy Scottish Power domestic gas/electric customer for many years. All payments by monthly DD and up to date. Then in Sept 08 I was erroneously switched (both supplies ) to BizzEnergy (a business supplier) I immediately contacted Scottish Power, they investigated and their Erroneous Re-Registrations Team eventually wrote back saying "Bizzenergy have transferred your gas and electricity by mistake. Your supplies will be transferred back to Scottish Power" A couple of months later, my gas was back with Scottish Power but not my electricity. Many phone calls ensued, "these things can sometimes take a long time", etc, and the thing was duly forgotten about for many months. To confuse matters even more, shortly after that our gas bill estimate was erroneously doubled by SP for 12 months, which led us to believe we were back paying for both services -- but this then was refunded to us in Nov 2010, which set the alarm bells ringing that we'd not actually been paying for any electricity. So now it is 3 yrs 11 mths after the erroneous switch, and out of the blue I get hit with a solicitor letter demanding £3,500 on behalf of British Gas Business. It turns out that Bizzenergy went into receivership and got taken over by British Gas Business shortly after I was erroneously switched to them in Nov 08. So in all this time, BGB had been "billing" me as a business customer. ( As a domestic user my bill for that period should have been about half of what they were asking for.) During this almost 4 year period - I never received a single bill from BizzEnergy or BG Business, nor did I receive any other correspondence from them (I wasn't expecting any) - I never made any agreements with BizzEnergy or BGB about tariffs or indeed anything else. Why would I ever agree to their business rates? - My meter was never read by BizzEnergy or BGB. All of their calculations in their unseen bills were based on estimated readings. My last actual meter reading was in February 2008 by SP, which was 6 months before I got hijacked I have now just switched back my electricity to Scottish Power, who were very happy to have me back with as a "new customer". So I'd like some advice please on how to deal with the demands of British Gas Business for money on bills I've never seen, on a tariff I never agreed to, for a period going back 4 years in time? Thanks for any advice!