Got a second Original Fat Chocobo

I applied to the 10th-anniversary sweepstakes and won the Fat Chocobo in May, I was really happy to win, so I thought I'd try for the Cumulus as well, I seem to have won as I was given a second letter from a GM, but it contained another Fat Chocobo whistle. For now, I have left the whistle in the letter. I don't know where I'm supposed to post this to resolve the issue, as none of the help threads seem like they're meant for this kind of issue, as it isn't a bug or a technical problem. Any help given would be greatly appreciated.