Found better flights for an award flight, can't modify it. I could call, but that would incur a fee. I'm not high enough in the pecking order not to have a redeposit fee, but it's my understanding that if I cancel instead of refund, I still have the reward certificate. How do I book against that? Does it show up in my account somehow? I've considered booking against another pile o' miles (that's not yet a reward cert) then canceling the first, then looking for another trip for the original pile o' miles.