It'll appear as pending in your cashback account in a couple of days, a week at the most. If not, contact MS. Then, it'll show up in your PP account after 60 days.
Oh, and it's back at 20%. I'm starting to have a theory about why the % fluctuates. I'm guessing it's based on demand. Demand on 35% was huge, so it went down to 25%. Demand on that was even higher for fear of it going lower. Then it went down to 20%, and then 10%. Then, people stopped bothering with it, so they raised it back up to 25%, then demand goes up, it goes back to 20%.