“Are you John Smith?” “No, we’re not.” (They’re asking in plural, so respond in plural.)

When they ask, “Are you John Smith?“, the correct tense of the an answer would be, “No, we’re not.”

You is always plural and it’s by design. They are speaking to the mister/master of the ship’s company. They are speaking to the master of their franchise person.

Since me not acting as an officer of one of their franchises, whether me answers as s man or as a group (of imaginary people), might as well have fun with it.

For those on the opposing team–who actually know what is going on–and the extent of the scam, they should be impressed by the plural answer: “No, we’re not.“