I have the same problem Open reach installed new fi re to house with new box I side.I asked engineering eer if I could rip out old wiring as it is 30 years old and ru s in plaster.He said yes and I would no longer need old box and plugged my phone into the new hub. The phone didn't work but he said it would take about 30 mins before bt bought my number over from my old supplier.After 2 hrs still still no phone so out of curiosity I plugged phone into old socket and low and behold I had dual tone.
I rang bt and was told exactly the same as you that I have to use old socket for my phone Mine is an overhead route so I now have 2 overhead wires coming to my house. One fibre and one copper.
This is a rubish Instalation and is ridiculous because the enginger told me that the new fibre cable also has a pair of copper wires inside. So why couldn't they have connected the phone to the coper wire in the fibre and then my phone could have worked off the hub and my old box and wiring would then be obsolete
I am going to put in a complaint and refer it to ofcom
A
At some point you will be transferred to Digital Voice which is supplied via the fibre and hub, your copper wire will no longer be needed.
Ofcom won't be interested in the slightest, you have service.
OFCOM are the Office of Communications, aka a Regulator.
They don’t deal with individual Customer Complaints. “Not their Job Mate”.
You would have to follow BT’s Complaint Process and if they’re unable to resolve it then they would issue a ‘Deadlock’ letter at which point you can take your Complaint to OFTEL to act as a mediator and their Decision is final.