Today they reported to me that the fault was now fixed. However I wasn't at home, so I took them at their word and thanked them.
Tonight I got home, plugged the handset into the BT line chwrrshccch and I do kchchrrk get a dial tone shcrrwrhkh and when the kkxfrrch phone rings ffthrprrpprth and I answer schrkzzkrpp the damn thing chrkghhhshrr what? ecchecchhlssqrzz Hello? chrrshh Oh bother *click*
Engineer booked to visit on the morning of December 27th. Oh, look, that's the same time as the NTL/Virgin engineer.