Roaches in Chicago apartment, i need to break my lease legally!

I recently signed a 1 year lease for a one room apartment in chicago. Upon the first move in day i found roaches. First i seen dead ones, then later in the evening they came out of my sink drain! About ten of them! I just moved out of my last apartment due to roaches. My landlord/the apartment manager did not mention any roaches habitation prior to me signing the lease. And it is the same leasing group i leased from before. When I asked them if there was any vermin, the manager stated no they spray every month. Now I need to break my lease because I cannot co-habitate with cockroaches for fear that they wil get into my items and move with me when i move. I am a very clean and tidy person, but i cannot live with the stress and terror of roach outbreaks in my home. i need to move out legally If they spray for roaches every month and there still are roaches then it must merit the problem as an infestation. It is a visibly older apartment building with 3 floors of one room and studio apartments. Any legal advice for my situation will be greatly appreciated.