Its really annoying that someone has been paid for that work, problem is your management company will almost always go with the cheaper quote and then you end up with this sort of work.
Ok so trying to be more helpful how does the supply get from the external CU to the stairwell lights at present, it must get there somehow.
If using that same route isn't possible i would have run a 6mm armoured submain from the external meter cupboard into the stairwell either buried under the slabs or following a similar route to the white conduit although dressed in much better so it doesn't stand out as much and then terminated that into a new CU in the stairwell from which you can run your socket/fire alarm circuits, and the existing stairwell lights doing away with the external one entirely. This saves you having to go out in the dark should anything trip and gives you the option of adding additional stuff in the communal areas in future should that ever be necessary. But all that costs money and i suspect your management company wont be interested, after all they don't live in the property so wont care how it looks and will only be prepared to do the bare minimum.
Ok so trying to be more helpful how does the supply get from the external CU to the stairwell lights at present, it must get there somehow.
If using that same route isn't possible i would have run a 6mm armoured submain from the external meter cupboard into the stairwell either buried under the slabs or following a similar route to the white conduit although dressed in much better so it doesn't stand out as much and then terminated that into a new CU in the stairwell from which you can run your socket/fire alarm circuits, and the existing stairwell lights doing away with the external one entirely. This saves you having to go out in the dark should anything trip and gives you the option of adding additional stuff in the communal areas in future should that ever be necessary. But all that costs money and i suspect your management company wont be interested, after all they don't live in the property so wont care how it looks and will only be prepared to do the bare minimum.