Air-conditioner not being fixed?

I've had a problem in my apartment with the air not working properly for a month now. The landlord is saying it's because it's so hot. The maintenance guy has been here 3 tomes to fix it an the actual air guy once and he supposedly put freon in the unit. Well nothing is working. The air blowing from the fans is not cool and it stays hotter in my apartment than it does outside. I know what the solution to the problem is and so does the landlord. I need a new unit because it's old as can be. They are not doing anything because they don't want to pay to have new ones installed. Most of the entire complex needs new units and a couple have new units. It's a cool 76 degrees outside and 83 in my apartment. I'm about to throw open the windows and hope it helps. My question is is what do I do if they don't fix it? My next electric bill is going to be astronomical because my air has been running non stop. I'm fed up with this and want my dadgun air fixed!