Duplicate Code-Darksiders 2 HELP,PLEASE :(

Contact the gifter

Talk to the one who gave you the code.
Also read FAQ.

No, you will have to contact whoever sent you the key and tell them what happened. They have to send you a new key or you mark the gift as not received on steamgifts. Nothing much else to do

Contact with the giveaway creator and tell him about the situation , if he won't give you a valid key by a week from the giveaway ending, you should mark as not recieved and until he won't give you a valid key ( And you will check its valid ) , don't remove the not recevied

Thanks for the help, I have sent him a email about the situation but I will have to ask for a valid key

it owuld be disgusting if he didnt send u a legit key , he deserves his account to be banned otherwise, so please i beg you, if he doesnt give it to you, PLEASE mark as not received