Hi Stefano,
I had exactly the same problem (see my post dated 27/10) and it's still not resolved. There may be some explanation that could help you in the answers although I didn't get very far myself. I will try and speak with someone during work hours tomorrow in order to resolve this once and for all. The number I have is 0845 600 7020. You can give it a go and if it works you can perhaps post the solution here.
Regards
Dear Stefano,
we would need you to send your access data to BT. Could you please contact them?
Thank you and regards,