Climbing to greater heights mission bug

[SaltyZoutzak]

So basically, I started the 'Climbing to greater heights mission' and in one part of the mission you must buy an Evil Ox horn, though it doesn't complete when you buy it. I literally bought it three times and it didn't work

[ShadowLane]

Once you get the quest item, you have to find Master Cho nearby and get to him.