The last quest I got in Krokotopia was from Sergeant Major Talbot, telling me to go to Marleybone and talk to Pvt. Kinchley.
When I talked to Pvt. Kinchley in Marleybone, then I got the Master of Oasis Badge.
Have you gone to Marleybone yet?
Also, here are a few side quests from Krokotopia that I missed in the beginning:
1. Mshai Djeserit in The Ahnic Family Tomb, and 2. Buikhu Djeserit in The Djeserit Tomb, and 3. Mah'rek at the Tomb of the Beguiler. (You don't have to actually do the whole dungeon. Just go in and talk to the first person there, then leave.)