Over a 5 year period I had BT here 4 times a year at least. Sockets, internal wiring, equipment , they blamed everything but never solved the issue. Twice I was told they would switch pairs but never did it. I moved to LLU and after months of perfect broadband the issue returned.
Provider organized engineers who came in with test kit I have never seen before. Instantly they see the problem and say it is the connection in the PCP which has notoriously bad connections and is obvious to anyone properly testing the line.
Despite all your wild rantings, that one comment (highlighted) indicates that you lack basic understanding of diagnostics.
A switch to an LLU provider would not cause a line fault at the PCP to go away! That's what they call a
non-sequitur. You probably had them checking all the tie-pairs at the exchange, throwing out duff comments like that!