Witcher giveaway problem

You're just going to have to wait until the free weekend is over and then re-sync your account. Until then, you won't be able to enter those giveaways.

You are out of luck for entering until you sync after the free weekend. It can stick around for up to a few weeks.

Look on the bright side, you can get it cheap right now if you want it. :P

Nothing to do but wait until it's gone from your account and re sync. In the future, don't sync during free weekends.