I was defrosting the mini freezer behind my bar and puntured the freon line on the aluminum ice cube tray shelf. Is there any way to repair this, or do I have to discard the freezer

It can be repaired but not by a patch. You'd need to replace the line and have the equipment to pump down the lines, dry the air and refill with freon. A good refrigerator repair man can give you a ballpark # over the phone. In most cases just head for Home Depot.

The repair will be very expensive due to the cost of evacuation and refrigerant. I have fixed many freezers with epoxy steel, surface must be extremely clean and try to minimize the opening, not the tube, with pliers. Epoxy steel works well with refrigeration due to the low operating pressures. Do not try this on high pressure refrigerants.

After you get the repairs done, and I am saying this in case you plan to try it yourself. You will have to have a service port somewhere in the suction line. I don't think your little
Mini freezer will have service valves or an access valve for you to evacuate the lines or recharge them, that is why you will need to install one in the line.