I suggest you do some surveillance
I also had the same issue, complain about the floor above me.
then the floor above me, said they did everything possible to stop the sounds.
after they moved out, I thought there was peace.
Then the sound came back, furniture screeching, loud stompings.
I took the staircase, went up 2 floors above me, no sound
3 floors above me, no sound
4 floors, - turns out to be this idiot who was doing all that noise at 4 am.
I complained again n again.
Finally the sound stopped.

Make sure you are complaining the right person, because sound can travel several floors.