Airpods 2 pro M/F/N/P rules

Does the rule apply to airpods 2 pro?

• M – purchased new (retail)
• F – certified refurbished by Apple
• N – replacement issued under warranty
• P – personalized with engraving

My story. I was sold AirPods Pro 2 whose serial number starts with “F” (refurbished) but was told they were brand‑new units (“M”). The seller insists the old “F = refurbished / M = new” rule was scrapped long ago. The noise‑cancelling isn’t working properly in the subway, yet the seller refuses to swap them for new ones and says I must take them to a service center. I don’t want to do that, because I feel I was misled: they charged full price for refurbished earbuds. I’d like to ask the community whether Apple has any official documentation on this topic that I can show the seller.

[Edited by Moderator]