question about banishing monsters diplomas

I got all 3 of the van helsing trophies last time the monsters were around. now I am unable to get the diplomas to complete the van helsing collections. how do I get the ability to get the diplomas again? i have a quest now to charge the diamond van helsing. I have the items but no ability to get the diplomas. any help would be appreciated. thanks

Unfortunately the diplomas were only attainable once through the full moon events. If you charged the diamond van helsing before you recieved the quest then you would not be able to complete the quest.

The only exception is if you add the diplomas to your wishlist and someone gifts them to you.