We have a problem with our downstairs neighbours, apparently it's 'noise' (we don't make any)
When we moved in we made sure to speak to them and say that if were making too much noise just let us know, so they came round and quite politely said that there was banging coming from the room above their bedroom, so we said we'd have a word with the guy in there and that was it.
About 2 weeks later at about 2.30 am our intercom goes off and we're like wtf, cue shouting and screaming and generally agressive tones of voice, they say theres banging, again we apologise. The next morning we go down to ask where the noise is coming from specifically and they stated it was coming from one of the corners in the room, we're like eh? cus there was a huge fuckin great big oak wardrobe in the room above so there couldnt have possibly been any noise coming from there.

They are a bit old like so theres no reasoning with them on anything.
A couple more times they've done this, buzzed the intercom in the early hours of the morning, they did it last night at about 4.45am.
We've tried the council, we've tried the noise people but apparently a complaint has to be logged at least 50 times before they will investigate further

We spoke to the landlord and other people in our building and everyone has a problem with them, the landlord said he was getting calls from them complaining about noise even when the property was empty for 2-3 months.
I dunno wtf to do, so far I've ignored them/walked straight past if they dart out of their flat in the mornings just to shout at me.
I'm not well, I can't have them constantly buzzing the intercom in the early hours of the morning and then to be faced with an angry tirade of verbal abuse when there is absolutely no need for it, we're not noisy, we lived below some incredibly noisy cunts in the last property we lived at and know full well how shit it is. It fucks me up having interrupted sleep.
Short of ringing the police the next time they do it, I have no idea.