Freezing my buns off in my apt. We moved into this apt 3months ago its getting cold outside and inside is cold?

our landlord say our thermostat is working but not offically on until it reachs temp in the 40s because the thermostat works with the weather outside but its like 47 degrees right now in NY and the water heater hasnt turned on yet she tells us to wear our jackets inside until then. The temp outside is 47 like i said but the thermo says its like 65 is it broken is the landlord bullshitting us