I cancelled an award that was booked pre 3/3. After a little over a week, the refunded taxes hit my credit card, but not miles. I called, and the agent could not find any record of my reservation. She initially asked me for when I requested the award. She then asked me for the confirmation number (I gave here the post 3/3 one). Both did not help. I had the ticket number but she said she couldn't look it up by that.

I finally manged to find the original confirmation email, and she was able to find the reservation only using the original PMUA confirmation number. The miles did hit my account within a couple of hours after that.