The amount of your monthly direct debit is no help. The figure may include estimates, and past under- or over-payments.our bill has gone from £43 / m to £149 / m since end of August !
However, if you can tell us the actual meter readings and dates, with comparative usage figures for the same months last year, it may be informative.
While you have this query going, please take some daily readings and tell us what they are.