And put a fan in front of it, put it on about 200 you'll be surprised how warm it will get in no time.
As for your heat situation: is each unit supplied with it's own hvac unit? (meaning heating and a/c etc) if so, don't bother calling the building manager, it isn't his responsibility. You'll have to call an authorized service tech for your make and model of heat pump if it's new and under warranty. if it is out of warranty then you can call anyone you like (look in the yellow pages).
First thing I'd do is check your breaker panel to make sure you haven't thrown a breaker. The fan is most likely on one circuit, and the heat/ac on another. BTW: is it gas fired? All electric? Does the building supply a source for it to exchange heat with? BTW: if it isn't gas fired, and is ONLY a heat pump (which takes heat or cool out of the outside air and puts it inside) the cooler temps outside can be your problem. Many heat pumps don't work worth shit below -5 C. That is why some systems in condo buildings use a central water system that provides a constant temp for it to either take heat from, or put heat into.