Unable to Obtain Quest Item(s) for Ancient Vows

I have never gotten the Kabala Sun Relic required for the quest Ancient Vows. I have farmed Keth for several hours in total and never got the item to drop. Is there anyway I can get assistance with completing the quest so I can get my +1 Charm slot and other quest reward?

I believe when I was playing through the campaign I didn't know what to do with the quest items or how important they were. I think I may have deleted the relics after not figuring out what to do with them. (I never looked anything up). I don't suspect that deleting the item means I can never get it again.

In case its relevant:
I am a level 70 Invoker Monk named Ralykar. I have beat the campaign on standard. I have been mapping for a bit now.