arctic freeze 134a+

I live in Phoenix Az and my 2008 Caliber will not take an AC (re)charge; low side it reads about 10-15 psi per service manual it should 46-70 psi. Attempting to use "Arctic Freeze Ultra Synthetic Refrigerant 134a+" from O'Reilly's. The heater blows warm after I went for a quick errand then...