Spent 8500 for whole new a/c and it stopped workin...

Spent 8500 for whole new a/c and it stopped working less then a month latter. Technician sent out had no idea what to do and changed the thermostat and left. It stopped working right after her left and he came back ... fixed it and left again. It stopped working! 80 and climbing in our home with a baby at home. Told it will later for another technician to come out. So frustrated and disappointed with this company.