I have a kelvenator 2. I have a kelvenator 2 door glass refrigerator that is not keeping

Question

I have a kelvenator 2 door glass refrigerator that is not keeping tempurature it has 2 fans on the evaporator.I had a company in to look at it and they took out the old gas and charged it with the proper amount.The technician said because it has a capillary tube that the charge has to be exact.He tok out 1lb 6ozs and the system takes 14ozs.It worked ok for a day then got warm the coil is frozen the fans are running but no air flow ?