Darth Nihilus PFP

Hi, I'm really hoping someone can shed some light on the issue I'm facing...

I've placed no.1 in my guild's Sith Triumvirate Raid: Heroic twice now, but the Darth Nihilus profile picture remains locked. I've tried using EA Help in game, but it's proven to be decidedly unhelpful, even after providing multiple screenshots by way of evidence. 

Is this a pfp that is no longer rewarded? I don't understand what the issue is. Any help would be greatly appreciated. 

Thanks.