man, i know that pain. those like economy priced office chairs. i bought some "amazon select" one a long time ago and am the sort of asshole who will try to fix anything so it lasts forever, and i have a lot of construction supplies, fasteners, adhesives, etc.... so when the arm rest snapped (which also had a structural support function), i was gluing and screwing parts back together, and the plastic would snap again until the thing was basically a death trap. i got real lucky and was dating this crazy hoarder pack rat at the time, and she had one of those really old school, 1950s industrial swivel chairs made of steel in some storage space.
it's like one of these guys:
the thing weighs so fucking much, is not comfortable to lean back in, and sounds like 3 angry cats fighting when you move/lean/rock in it... but i've had it for 10 years and it's a goddam lion of a chair. i bet it would be the only thing salvagable if my house got hit by an artillery shell. i bet i could like oil it, paint it, and reupholster it and sell it on some website for a shitload, but it's my workhorse.