Presumably you speak to the people at no. 14, else you wouldn't know the product.
As dect says, it may be worth asking them which ISP they went with. You say TakTalk won't let you keep your number, but it could be that's who they went for.
If so, it's worth asking
Pulse8broadband. They use TalkTalk Business Wholesale and complaints are very rare. But emphasis the keeping of your number when talking to them. It's possible BT Wholesale just haven't got round to updating that checker, with Covid and people working from home.
AIUI Plusnet don't do FTTP at the moment anyway, so you will need to migrate somewhere.
Another solution to the keeping of your number would be to port it to VOIP. I know very little about the safest process for that, but there are plenty on these forums who do. Anyone with an Openreach circuit will have to do that anyway within a very few years (2025 I think is the cutoff), as Openreach are withdrawing their landline phone service. (Which BT Wholesale and therefore Plusnet use).
(Does a quick search)
TalkTalk do or at least allow VOIP:
See this 2018 Community thread. Or I expect you could port to one of the popular specialist VOIP providers and take the the TT data-only fibre service. I suggest you ask for more detailed advice on these forums about that - as I said, I'm not qualified enough on that topic

. I do know that SipGate mentioned in that thread is used by many here and has been around for many years.
My broadband basic info/help site -
www.robertos.me.uk. Domains, sites and mail hosting -
Tsohost &
Ionos.
Connections: OnePlus 8 Pro max 165Mbps down, 24Mbps up on Three, and B311 4G, tbb tests normally 35-45Mpbs down, 65Mbps off-peak, 9-24 up.
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The EU’s multiple failures are due to a deeper malaise .... What malaise? The EU’s formidable immunity to the smallest amount of democracy. New Statesman Feb 2021.
Edited by RobertoS (Sat 17-Apr-21 22:10:28)