Renters right/ help

Hello all! I currently stay in Cypress tx and I am having issues with our complex. we have been having many issues, but our biggest issue is our AC. yes it works but our house doesn’t go below 75 degrees even if we put it under that number. We even tried putting it at 65 and it stayed above 75 when it was in the 80s/90s. we have contacted our maintenance 3 times and each time they come and say there’s nothing they can do. this is starting to affect my husband and i as we are not getting any sleep due to the heat. it feels like constant heat flashes ( i’m 26 ) so i know it’s not that lol. i just don’t think it’s fair we have to pay more in electric because we’re using fans on top of the ac. Anyways. would this be a reason to break our lease since maintenance won’t do anything to fix it? we also had a concern about mold and when we told the office they come with a little machine and he looked at one wall and said there’s nothing and basically you live in texas so it’s humid, even though there is definitely a mildew smell. So i just feel like it’s laziness. Sorry i know it’s a lot, but thanks in advance.