I have a brand new 4 ton AC unit that is blowing cool air but not cold. It replaced a 3.5 ton that really kept my house nice and cool. The Company that put this unit in along with a new heating system keeps telling me that it is working properly, Yet the temp outside was 84 and the temp inside climbed to 81 and unbearable. He got his little camera hose to put into the vents and said that everything seemed to be working properly but it is hot in my house. I asked if he could turn the temp down on it and he said no. He keeps saying that it is the fact that I have one thermostat and 2 levels. My other AC unit worked fine and you almost had to put a sweater on but was not compatible with the new system. What can I do?