Assassin's Creed 4 Weird Problem

I kept downloading this game on steam on and on and it keeps downloading from the start, I have the standard edition

now I see that its space have become 20.6 gb instead of 17.8 and the freedom cry DLC is now unlocked for me without even buying it ! anyone else had it for free or it is just me ? I restarted steam on and on but the DLC tab about the game includes the DLC which I haven't bought .