Did you ever establish your cabinet number, and if so has it changed?
It could be that you were given a half story from somewhere. It is possibly true, but maybe not the main reason.
What might make sense would be if a new or spur FTTC cabinet has been installed closer to you in order to comply over the medium term with the 10Mbps USO for BT in your area. With Zen and therefore you being spin-off beneficiaries. This could well be cheaper in this particular case for BT Group than rolling out FTTP at this point in time.
My broadband basic info/help site -
www.robertos.me.uk. Domains, sites and mail hosting -
Tsohost &
Ionos.
Connection - Three B311 4G, tbb tests normally 35-45Mpbs down, 65Mbps off-peak, 9-24 up. 1+ 8 Pro max 80Mbps down, 24Mbps up.
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To argue with a mindless bigot is foolish.