Our central air unit isn't cooling down the house. It blows cool air but no change in overall temp or comfort.
We've been in our place three weeks and the ac unit is brand new.

Brand new house or brand new unit. If house, contact builder. If unit, contact. AC installer.

I called the selling realtor who put me in touch with the AC installer.
The AC installer said it was a cracked copper line that leaked out the freon and that it would need to be replaced. He said it likely happened in shipment or during installation.
He is working on the warranty info, but in the mean time he recharged with freon until the replacement could happen.