Neighbours banging on their ceiling/our floor? HELP!!!!

Apologies about the late reply sunshine, ive had internet issues for a couple of months!, is this problem sorted? If not, which block are you in? If you are in the shared ownership block I would suggest firstly having a quiet word with your neighbours and if that is not fruitful then look into having a word with south anglia. Its always possible that it is the toddler and isnt agressive but if you dont feel comfortable with having a quiet word then just leave a note for them explaining the issues it is causing.
Chris

Our downstairs neighbors keep persistently banging on their ceiling / our floor for no reason, since May!
They do it aggressively, with force and do it several times every day at random times during the day e.g. 7am, 11am, 3am, 6pm, 9pm, 11pm, 1 - 3am in the morning.
There have been some really loud thuds and wallops that have made the flat shake, windows vibrate and we have felt tremors across the floor too. They pick different areas to bang under so sometimes bedroom 1, lounge, hall etc...and it just starts out of the blue!
It appears to be for no apparent reason and we are good quiet neighbours e.g. no parties etc...who keep to ourselves.
Its getting worse and only last night around 8pm there was like a big thud under the floor in my room and I jumped up!
We have shouted through the floor a few times during the banging, "Please stop banging the floor"....but they carry on. And a few times it has felt as if they listened to where we were in the flat and then came and banged under where we were.
This all makes us feel alarmed, distressed and worried and we really do not know what it going on!!!

A few weeks ago there was some really violent banging in the evening and when it stopped, we then heard a knock at the door. I looked and saw a couple with a toddler and they were standing outside, but were looking hostile and defensive. So I did not open the door. The man rang the doorbell then and I am assuming that they wanted us to open the door to them. But then they went away quickly down the stairs and a few moments later the banging started again!
So I think that the downstairs neighbours may have come to our door and as they know our door number now, I am surprised that they have not left a note explaining why they came in our post box outside or why they never left one under/by the door.
This makes me think that the banging is deliberate possibly malicious or to annoy/alarm/threaten because otherwise if it was something genuine they would have left a note or something. And as mentioned when we ask them to stop, they just carry on sometimes late into the night and we not been sleeping too well lately.
We are worried about why they are banging so much.
This has been and still is very stressful living situation and we do not know what to do.
I would really appreciate it if anyone can please give advice/help on how to deal with this all. A big thank-you in advance!