UPLAY, STEAM (Far Cry 3)

Karoch, guys, the topic is this, one of my friends exchanged a Steam account with a dude, after about 3 months, I exchanged with him for this account, there are many paid games on the account, one of which was Far Cry 3, I installed it and wrote to me that I will need to write a code in the future, copy it or write it down, I installed the game, launched it, he started installing UPLAY for me, I registered there, entered the key there, but I was told that the key was already activated. MB how can this be solved? Tell me pliz.