Hi there and good morning (from Romania)! I think I did not get the rewards when I killed the Shadow Valkyrie (Level 50 Valhalla Coop Boss). Could you please check? Thank you!
Best thing to do is to submit a ticket here: http://support.kanoapps.com/ But be patient... it may take a little longer than usual for them to respond because of a change that took place across all games today.