When there is an irregularity in your consumption and you see a lot of disparity between the kW consumed and those invoiced, a file is opened to investigate what may have happened and if the possible fraud is real.
In the case of receiving a letter of this type you will have to contact the distributor, their number and different ways of contact will appear in the same letter. They will inform you of what you have to do to manage your case.
The marketers here can not do anything and you will have to process everything on your own