> one with severe medical condition... bought a rolling chair and likes to roll around his apartment [all hours during the night]... denies he rides the chair and then uses his medical condition as an excuse
I mean... is his medical condition related to his ability to walk and sleep well? E.g., does he:
1. have trouble walking
2. can't afford a wheelchair
3. has continence issues?
That would explain rolling around at all hours of the night. And sourcing him some cheap/free mats/carpets to cover the floor between his bed and bathroom could help you sleep better.
In any case... sorry you have to put up with that. Having noisy upstairs neighbors sucks.