You may have to do this via WhatsApp or messenger as they never answer the phone.
Once a complaint is raised you will get a phone call offering you compensation to Seattle the complaint so that it can be closed, I got £20.00, so a settlement is reached and complaint closed. They do not like unsettled complaints!
I do this every few months as they ignore your request and keep sending notifications to fit a smart meter,.
Just bin them, they cannot do anything without your say so.
They have now moved to letters which say my meter needs changing as itís out of date, just bin them.
I have had these for over a year,
Just bin it, do not talk to them.