Advice regarding next action to be taken

The ceiling of both our bathrooms is in dire condition (broken & rotted) as a result of the top floor bathroom problem (water leakage).We are tenants, the floor above us has a new tenant too (who claims that it is not her responsibility and that the landlord is not contactable).The management also says that they are trying to contact the landlord from the flat above (who happens to be a doctor).After complaints from us for last 4 months and when we made a noise they now told us they have made a telephone complaint to the Environmant & Hygiene Dept.We have no proof of this and noone from there have tried to contact us too.They refuse to give us the top landlord's number for privacy reasons.This is in Discovery Bay.My question is what is my next action? My house is now smelling very bad. What are our rights as tenants? Does the privacy legality hold than the public health issue (last example being SARS).What can we do now? Can we call the police and get it fixed/sorted out? Is it the top teneant's problem to get it fixed and charge the landlord through rent? (as she says she needs to use the bathroom and may not fix it)? Or is it the managements' problem (we pay manage,emt bills) or do we leave the flat?

Thanks in advance and any advise would help.plessssssse

Thank you WPR Ltd.I shall keep you posted .Thanks for yr advise.