Need to get CityFibre to contact my building factor

I live in a multi-storey block of flats. CityFibre has already brought fibre to the entrance of the building, but it hasn't been installed throughout the building.

I've tried signing up with 3-4 different broadband providers. They all let me place the order, but when it comes to the installation appointment, the order gets cancelled. The reason given is that they don't have the building's permission (wayleave).

I've contacted my factor several times, and they keep saying the issue is with CityFibre. The problem is I can't find any way to contact CityFibre directly to get them to speak to the factor.

Has anyone been in this situation? Is there a way to get CityFibre to contact the factor, or to start the wayleave process?