No one on the forum is BT, except for the ocassional mod. Everyone is a customer just like you - and most of us have had problems, gone through a learning curve on how it all works then hung around to try to help others with their problems.
You've obviously had a problem and as it's to do with billing/connections this needs to be sorted out by BT. No one from BT routinely read these forums, but you can contact the mods here who are BT and have a good reputation for solving problems. They normally respond within 3 working days.
By the way, I think that geo1986 was correct, the MAC code is for migrating telecoms/broadband to another supplier whereas the PAC code is for mobiles.
If you use the link in my post above (no. 6) you will be able to contact the mods and they will almost certainly be able to help you.