BT Nightmare

Socialise and chat about other areas of your life
Anyone have any effective BT contact details to put in a Complaint? I have been going round in circles trying to sort out getting on a cheaper Tarriff. Was assured being on ESA and filling in their form would be enought; but no. I'm to be sent another form, and needing to include a copy of proof of benefit. I spoke with BT Basic department, who insist they contacted DWP, who couldn't verify I'm on ESA. Had endless stress for the past 4 years now.....not needed.

No doubt they will treat each complaint with equal contempt ?