The A/C involves three systems: the mechanical system w. freon, the vac control system and the electronic push button controls. Unless all 3 are working properly you can have cooling problems.
Are you sure that all the vac control elements are operating correctly? Especially check the fresh air flap located behind the glove box. It is easy to remove the glove box insert and visually inspect the flap operation with the A/C on and off. There are two vac elements that control the flap. When they fail the flap stays open and allows outside (hot) air into the cabin. The flap is open when it is toward the rear of the car and closed when toward the firewall.