Jim's put in some good points, his last been especially valid!Just add beer
Hey thats not a problem, its not your job to document it, its just it makes for a wounderfully visual letter, "from this x, to this y". Don't think the landlord, the freeholders won't care that this hasn't been fixed, they will loose money, they will damn well care! Never mistake incompetence for malice!
Ok so its a small block, that normally makes this eaiser!Because sometimes there are many problems which all need fixing in turn, you might have to be the bearer of bad news. Regretably its a **** situation, but inaction will make it worse, even if your not popular for bringing it to their attention!
If you can take a pic of the ceiling caving in, say its getting worse, tell you landlord.
If no response, get the concil envolved they are normally really prompt on these things!
But before going to that option just try and make sure its not a failure of communication with your landlord n the freehold.