I call
I learned my lesson the hard way. After hours of checking flights from the website I finally called. They had seats that were not listed on the site. I just called the regular World Perks number since I am not an elite.
In the end I booked 2 WBC tickets - Perk Saver no less - from Tampa to Nairobi on pretty much the days I wanted. Now it took quite a few calls, but it was worth it. Yea it cost $15 for them to book it but I wouldn't have got the tickets otherwise.
My advice for what it's worth is to call and have them do the research.
enjoy,
Duane