I'm not in HVAC, but in the house we just moved out of, we had problems with the A/C 5 out of the 7 years we were there...and it was a brand new house.
I'm assuming a/c unit and blower are coming on, yet it's blowing warm air? As long as the blower is coming on, chances are you're low (our completely out) on freon, and the unit has probably frozen over. Go outside and look at the unit that goes to your apartment. Check the lines coming from the unit and going into the building. If the unit is sitting in the shade, it will probably have some ice on it. Tonight you'll really notice some ice on it if you leave it running (although I wouldn't, as your only making the power meter spin faster and not getting anything in return).
That's the problem we had 5 out of thr 7 years we were in our old house. Turns out our issue was the valves were not put on properly when the unit was installed, and slowly leaked out freon over the course of a year.
How old is the unit in your apartment?