The store cannot refuse to do a wfg exhnage in the 14 days. they obviously dont like to because that imposes on their commision but they dont have a choice. especially if you ask for a supervisor in the store.
Devices purchased online and shipped have to be shipped back for the return. It might work the same if they are exchanging it for a different model phone.
I'm most definitely NOT a VZW employee. If a post answered your question, please mark it as the answer.