Ah - found the contact details for the Mods... why make it so **bleep** difficult???
It took ages to work that out!
BT Support really is a joke!
I wonder how much clearer could it be
"Can you please drop me over an email with your details? You'll get the contact the moderators link in my profile".
So, after a rather large number of phone calls, we have a solution.
It turns out our account did not have the correct settings applied, and so there were no previous bills displayed... just as I had been saying.
In the end I had to send screen grabs of the website pages to prove what I was telling BT Support.
They have now found the issue and corrected it...
What a **bleep** palava!