As a Costco wireless sales expert (per my nametag lol), technically you can make a return within the 90 days per Costco's electronics return policy. Anything and everything is a return, never an exchange, simply because you always have to go through the checkout and buy the new phone. Typically, a kiosk will only "exchange" for the same handset if you are past the 14 day trial period given by the carrier. And it is a one-time "exchange". Some kiosks do not even allow a return past the 14 days. Each location is a bit different, as Costco management makes those decisions and we are only vendors.