Openreach is NOT part of BT (Consumer/Business - the bit we all deal with), although both are part of the BT Group of companies. Blame Ofcom, they are the ones making life difficult for every service provider dealing with Openreach, BT included.
I would be really surprised if the Openreach chap actually spoke to anyone at BT (or vice versa), as that would be in breach of both of their licence agreements, and Ofcom would be very interested in that - I would imagine both would be instantly dismissed, and both companies take a hefty fine. Everything has to go through that wonderful electronic system, ECO-BB, that anyone who has ever worked at an ISP will know and love
. That includes BT.
There are a small number of people in the wider "BT" who are allowed to talk to both Openreach and the "BT" that consumers know - in a previous role, I was one of them, but he rules (and tedious training and constant refreshers) were very stringent.
As said, pissing off end users is Ofcom's mission, but making life hard for your ISP, and ensuring prices are high.