I have had a similar experience as others, in that I was given a hugely over-estimated bill (it went up to £10k before I had the Ombudsman step in), and they didn't seem to think there was anything wrong with this estimate. Throughout the whole year, it was a constant fight that went nowhere. They didn't even question why a single person in a small house would use an industrial amount of energy, but they were hellbent on getting the money from me anyway. Their customer service was absolutely no help, they just kept saying "we're working on it" while demanding thousands of pounds from me (and despite my meter readings being incorrect, which they knew about). I'd been warned about them for years and only became a customer when they absorbed the company I was with. Truly the worst experience I've ever had with an energy company, and it only lasted a year. Avoid this company if you don't want to pay more than Amazon in energy bills, be gaslit, or have all your concerns ignored. Oh, and they won't apologise for any mistakes they make either. I'm happily with Octopus now but I'm sure BG will find a way to demand more money from me somehow...