I believe --but I'm just guessing by what you're describing-- that this is the part you need:
Samsung Refrigerator Freezer Door Handle Support DA61-08077A/3957815
Here it is through Amazon $28.60
These will fit the handles for the RF18 -series refrigerators. But again, I'm not sure if this is what you're describing or not.
Here is a generic and kind of cute video featuring kids fixing/adjusting a handle but it doesn't pertain to your situation as theirs doesn't seem to have an actual cracked end piece but just saw it as I was searching around, lol --I didn't watch it real closely but I think the screw became loosened up on theirs:
ETA: Here's a professional installation of the part I'm thinking that you're describing if you need it but it sounds as if you do not as you know the part that is broken and how it is replaced but just in case I'll post it below ...it is not of your exact model but it should be similar mechanically: