The Sobi Robe you received as reward has a tag sewn into it which indicates that it was actually meant to be sent to Reshanta. Take it to Cymaon, a supply officer based at Teminon Fortress.
Step 1. Take the Sobi Robe to CymaonA quartermaster at Teminon Wharf. He uses his position to his advantage., a quartermaster in the Abyss.