ISP refusing MAC request

[yoda]

greetings,
I've asked my ISP for a MAC code and they have said no on the grounds that acording to them my account is in debt.
I'm outside my 1 year contract and I pay by direct debt.
When I phone up to ask them how much my account is in debt by they say that it isn't.

Is their a 'formal' procedure or an agency I can complain to to force them to give me my MAC code?

 

[yoda]

thats what I want to do, but I've herd grumblings that when people cancel BB the ISP still leave 'markers' on the line so that you still can't go to another ISP without a mac code?????

 

[yoda]

whats the number?