need help. who to call?

I'm in Wisconsin but they have something for every state. I live in an apartment with a slumlord manager. Among the list of gross things, floor breaking, and no smoke detectors we have no heat. The lease says we get free heat but what they "forgot" to tell us is that they control when it goes on and the temperature it's at. They don't turn it on until nearly November and keep the temp low. It's getting cold now and my four month old baby has to be bundled up in the house. I called the building code/inspection people who come out but they said they can't do anything it's not their field. They said it MIGHT be a legal issue. Does anybody have any clues what I might have to do or who to call to get this resolved? I tried talking to the manager about it last winter and nothing was done.