I left Sainsbury’s Energy last year but it keeps inflating my final bill

Two readings but one less digit has taken what I owe from £32 to £1,841In September 2017 I left Sainsbury’s Energy after 18 months as a customer. During that period, my gas meter was read twice and I was told I was paying the right amount. I was given a closing balance of £32.Fast forward to this February and I was staggered to receive a new final bill from Sainsbury’s for £1,841. I complained and was sent an amended bill for £1,079. The firm claimed tha