After I talked to all the related NPCs, I still can't get in Roppongi Mall. Btw I have ever forfeited this quest before, thought of being able to reselect quest. Does it cause the problem?
I have an operational unit and it won't let me drop it, but you can NPC it for 1 meso. Perhaps you need to kill dunas v2 again to get another?
Thank you for your report, this issue will be resolved in the next patch. A GM will be in contact with you to arrange a refund.