Some ISPs take heavy criticism because of Openreach delays, sometimes unfair as they cannot do anything about it. I've just seen how Openreach themselves can have problems.
My phone line comes 30m from a distribution pole across a busy road to the top of my gable wall, where it is secured by a ring bolt. I noticed this bolt was very severely corroded and called Openreach, saying that as an engineer I considered it should be replaced within the next few months. The operator told me the technicians had 48 hours to respond as emergencies such as road safety related items had priority.
The Openreach fitter arrived 18 hours after my call and replaced the bolt within 15 minutes, saying that the bolt was one of the worst he had seen. While installation delays must be infuriating, in this instance I thought OR did a good job.