I am the supervisor
If there’s one person we should all feel sorry for, it’s calling center employees. These guys probably get an earful of all kinds of questions, from the rational to the downright crazy. And you can bet that they have to deal with Karens all the times. Giving sarcastic responses are probably the only joy they get out of their whole workday.
But what happens when a fussy Karen asks to speak to the supervisor? According to the OP and several more who can vouch, the call center employee will put the caller on hold, wait a few seconds, and pick up the phone as the supervisor. Surprisingly, no one has ever caught the call guy for doing this.