What should be my next step to follow if it is the 5th time In less?
Well, you could bat you head against a wall with fruitless complaints to the local health officer and written demands to your apparently heartless landlord. In you situation, I would spend $120 or so to get a 5 or 6,000 BTU window unit, rather than continue to risk living in dangerous heat. When you leave, the window unit you bought is yours and you can take it with you.