DLC

Then wait till he give you the soundtrack or click on not received after the 7 days.

Why he should? You didnt gave him the key for the soundtrack.

I've once been banned for a while for this. This is a key to the game and not the DLC. I can't mark as received. You may delete the giveaway instead. I haven't used the key.

You made a false GA. Only people who have the base game can enter for DLCs.
If you don't give the winner the DLC you'll have a bad mark on your account.
I suggest you read the FAQ.