A/C outside unit running, inside unit not running?

I want to ask this so I know what to tell my landlord when he sends over his "handyman" to fix my a/c unit. A month and a half ago, my outside coils froze, cutting off the cool air coming inside. All units were working. Handyman comes to my duplex, says refrigerant is low, fills it up. It works for a month and a half. Today, inside unit stops working. Outside unit is running, coils are frozen again. I let it thaw for a few hours. Turned it back on, outside unit running is running, inside unit isn't. What could be the problems I relay to the handyman?