Accidental badge conversion.

Check your email, and possibly in-game mail - typically this sort of things would result in the ticket being escalated, which can make the icon disappear. A mail is sent to let you know it was escalated.

Blizzard did change their policy to allow GMs to reverse emblem exchanges under certain circumstances, so it's quite possible. You could put in a second ticket just in case the other glitched, so you have one well within a reasonable amount of time. Then if the restoration occurs, you can just close that.