Unable to obtain Ark Angel Galka Trust after completing quest with full inventory

[Gameesh]

I did not experience this bug myself, but a friend of mine did and since he doesn't have an account here I'll list it for him.

Platform: Windows
ISP: ???
Type of Internet Connection: Wired
Internet Connection Speed: 45Mbps
Date & Time: Nov, 23, 2016
Frequency: All the time
Character Name: Ariegeerlofse
Race: HumeM
World: Phoenix
Main Job: Summoner, level 99
Support Job: Scholar
Area and Coordinates: La'Loff Amphitheatre
Party or Solo: Solo
NPC Name: N/A
Monster Name: Ark Angel Galka (Very Easy version)
Steps:
1) Acquire the RoE quest 'Quell your Rage' (listed under RoE quests 3).
2) Flag said quest.
3) Obtain a 'gem of rage' Key Item (bought with merit points).
4) Travel to La'Loff Amphitheatre (near Home point #5 in Ru'Aun Gardens) and enter the BCNM area.
5) Target the circle and enter the fight (in his case, he chose Very Easy).
6) Have a full inventory.
7) Summon trusts / buff up and proceed to engage and win the fight.
8) The rewards are dropped and the RoE 'Quell your Rage' will be completed.
9) A message pops up that you are unable to retrieve the item 'Cipher: Trust AAGK' due to having no inventory space.
10) It's impossible to claim the reward from the RoE menu, since the quest is unrepeatable.

Things he tried to fix / retry this RoE:
1) Spoke to Jamal again in Ru'lude gardens
2) Tried clicking on the completed RoE, (de)selecting it or accessing it in any shape or form
3) Zoned out and back in
4) Logged out and back in
5) Obtained a new 'gem of rage' and defeated Ark Angel Galka once again (this time with room in the inventory)

None of the above worked.

My friend is still unable to obtain the Cipher for AAGK, and this also means that he can't get or even start the quest to obtain the Cipher for AAEV and any possible future Ark Angel Trusts.

I hope this bug can be fixed in some way. Thank you for your time

[Catmato]

Check the Mystic Retriever by the Port Jeuno Mog House.