Water damage through ceiling

Other

Hello - I own a flat in a small apartment block. My flat is located on the ground floor and directly above it is another flat of exactly the same layout.
The tenant in the flat above noted a leak in the bathroom which has been ongoing for several months (since summer?) without being recognised/attended to until before Christmas 2013.
Water had leaked under and behind the bath and the water has soaked through the wall (?in part MDF) and ceiling in my apartment`s bathroom with dark stains and mould appearing and tiles on the wall around the bathroom window loosening.
I have tried to contact the owner of the flat, but this has proved very difficult through either the tenant or the management company looking after the apartment block (who did not feel they could give me the owners address/phone number/e-mail), but have now at least forwarded a letter to him, around 2 weeks ago, to which I have had no reply so far (I still don`t know where the owner lives, but not in the same town).

Do you know what the situation is in such a case?
Should the owner of the flat above not pay for making good the damages in my flat (in addition to finally getting the bathroom of his flat attended to)? What do you do if you can`t get hold of somebody? At least he should have the courtesy to contact me (I have provided all my contact details in the letter).

I have in the meantime had to get a decorator to re-paint the ceiling and get the grouting and tiles done as I had to get the apartment ready and in rentable condition for the next tenant.

What is your advice?

Yours sincerely,
CH