I've had Far Cry 4 since release and only just getting in to the game. The "Hand of Justice" achievement (Eliminate 3 Pagan's Wrath convoys) will not unlock even though in the statistics it says i have 3/3, i have done 5 in total. Also, "Caretaker of Memory" (Find 10 lost letters) i have 10 but still no achievement. I had this trouble with the "Misdirection" achievement too (Distract 15 enemies with rocks) which eventually unlocked when i was just driving around.