This "feature" is really rough around the edges. I screwed up my reservation by reapplying the certificates to my booking which triggered the system to buy points since I was short points. Called in and the agent sent an email so it "should" be reversed within 4 business days.

Went back into the reservation and at one point the system offered to return the two certificates to my account, and would instead deduct 2,000 points. Turns out it actually meant points advance (didn't screen shot it, but there's no reason I'd have selected it if it said points advance). It was too good to be true so now it's a points advance reservation. Went to go reapply the certificates but it wants an extra 2k points. The hotel costs 37k for the first night and 33k for the second night. I have 1 35k cert and 1 40k cert (expiring in that order). Somehow the system decided to use the 35k cert on the 37k night and the 40k cert on the 33k night.

WHY IS THE WEBSITE SO AWFUL TO USE. (Rant over)

(JK, rant not over, now I get a 800 error when I try to apply the certs to the reservation)