Unless your exchange has an isp wth LLU ( itsown equipment installed at the exchange) it wil not matter who you go to as it will be down to openreach / BT wholeasle to provide the connection there
As to contacting the forum mods you will have to contact then as they need all of your details EG account numbers phone numbers e-mail details etc.
Please do not post them here as they will be deleted as personal details cannot be displayed for your personal details would be on public security this is a customer to customer self help forum the only BT presence here are the forum mods this is a link to them
they normally reply by email or phone within 72 hours directly to you
Breach of contract, move on. There are plenty of ISPs out there, even those that use the same BT wholesale infrastructure (or are owned by BT but operate independently) can, and will, do better than this.