Re: We cannot spare the money to hook you up...
"although we sold the one we had"
Not even that. It was demerged as a separate company, AFAIK because BT didn't like the amount of money paid in the spectrum auction.
In fact, I wonder what it actually cost BT to do that. Staff TUPEed into O2 at the time would have been in the BT pension scheme. Presumably there would have been a pension scheme with equivalent benefits set up for O2. If the BT scheme hadn't been in deficit it would have been a straight transfer of the appropriate proportion of funds from the BT scheme to the O2 scheme. But as the BT scheme has been in deficit for years did BT have to add in extra to make up for the shortfall?