[Asterisk-Users] BT ISDN30e and presentation numbers

[Asterisk]

I've just got off the line from my account manager, and she insists that I
can only have one presentation number per ISDN30e bearer line. Oh, I can
also have any of my ddi numbers presented ...

We have several business units each using the ISDN30e, and I wanted each of
them to present their own numbers, so that anyone doing a 1471 would then
call the appropriate number. Asterisk recognises these numbers, and sends
them to the appropriate destination.

If I have a hundred different DDI numbers presented, why can't I chose
several different numbers that aren't a DDI ? 

Am I being hoodwinked ?

Julian