Prepaid stay hadn’t been charged yet, so I wanted to change payment card to SPG Amex for 40 off 200 offer. Somehow this took me to the rates page, where it offered me the (low) currently available rate instead of the (mediocre) prepaid rate I agreed too. I then click “update” with the new rate; nowhere does it say “cancel.” So now I get new confirmation email, same confirmation number, new rate, $100 saved. No cancellation email generated either.

Unclear why they allowed modification of prepaid rate. Did I just save $100? Is it a trap? Will I be charged twice? Or are they just that bad? Bonvoy!