I tried/meant to post a link to this thread http://community.bt.com/t5/Bills-Packages/Direct-debit-taken-today-assured-3-times-it-wouldn-t-until... ; I don't know what went wrong. It was the advice about the Direct Debit guarantee I thought might help.
I'm really sorry about the fault with your line and the way this has been dealt with. Please use the 'contact the mods' link in my forum profile under the 'about me' section to send in your details and I will be happy to help. You can find the link by clicking on my username.