Awful company! I was loyal for over 13 years (never missed a bill). I then moved house and had confirmation I had paid in full and closed the account! 6 months after I moved out I get harassed for more money for my previous address that I don’t own/live at any more. N Power say they’ve made a mistake and forgot to add up my bill correctly (even though I was on a smart metre) and it’s taken them 6 months to realise?! I called up and explained my situation to be told I had to pay it due to someone at Npower making a mistake! They put me on hold so I could speak to a manager and then hung up on me. It might be a coincidence but it happen right before they closed at 8pm :(