That’s true, but here they are marketing in a way that gives false hopes: Already own one? Complete your pair.It's how buy one get one free has always worked since the dawn of marketing. To be precise... "buy one NOW, get one free". If you already owned a pair of shoes in a new BOGO promo, you can't walk into the shoe store and demand the other for free.
I can complete any kind of pair any time if I like. Just suggested they should not give false hopes, as it’s a discount, not 2 for 1.