For last two months, I've been trying unsuccessfully to leave BT as they are getting too expensive. However, I was told that I can't leave with Early Termination Fee. I have given them the reason for my leaving - increase line rental and I was not notified. They told me that they sent me an email to a BT/Yahoo email which I don't use and my account is registered against my gmail. Apparently, I've opted in for email communication. When I asked them to provide evidence, they declined.
Now they are sending me a letter of deadlock and the bottom line is that I have to pay. I would appreciate any assistance with this, e.g. my legal rights and Ofcom rules.