I've lodged a formal complaint with BT but I'm not holding much hope of anything more than a further apology. All a bit strange in this digital world given that the number that has "disappeared" was originally allocated by BT.
Check out the following link
Ofcom insist on consumers being able to port their number. Fines are imposed for Companies that are obstructive. I’ve made the point to the Communications Ombudsman that BT should be under a similar obligation when carrying a porting that is entirely within their own network.....