Presumably you had some read the old meter before it was replaced, and who verified that the new meter was set at zero when it was installed
Prior to the new smart meter installation, I submitted a reading. Airtricity then did an ACTUAL reading which was no different to what I had submitted as the house is unoccupied and the power had been turned off at the mains. Then ESB installed their meter. I assumed that the meter would be set either at the last submitted meter reading OR 'zero'. Airtricity did an actual reading on the 20/11 and based on a zero reading now want me to pay €300.