penetrating damp from rogue neighbours

[swimmy]

The adjoining property (terrace houses) is causing a damp patch bang in the middle of the communal wall...after visiting my next door neighbour we realized their bathroom was the cause - tiles installed on the wall without proper backing - not to mention the bathroom has no windows and vents are installed on the ceiling (not the roof) so the vapour from the bathroom is released in the loft area (which I sealed for obvious reasons).
After years of polite notices the company who own the house still refuses to do a proper job to rectify the problem except for instructing their tenants to be more sensible when using the bath tub or similar (clearly after some complaining I noticed some mild improvements but then the problem returns later on causing moulds smells and all the nastiness associated by it....so I bought a dehumidifier and air purifier (with associated extra energy costs).

Now, being tired of being ignored after years of complaining (they simply don't care) I've decided to take more drastic measures - after a bit of research I've found out about "party wall surveyors" but apparently these only act to monitor building works initiated by the owner (me) but the source of the problem is next door...so, is there a way I can engage party wall surveyors to impose works needed in the adjoining property? (e.g. installation of aqua panels) and forcing the offending party to foot the bill too?

Maybe it is just wishful thinking....any suggestion appreciated.

[wes56]

call a party wall surveyor specialistor any other RICS an get an opinion. any investigator would have to be qualified an prove the damp is coming from next door