I just had the worst service experience at the Covington Verizon store. They sold me a 4G extender that would not work with my iPhone 5S as confirmed by the Verizon web site, Verizon tech support and a separate Verizon store. The Solutions Manager (Christopher) at the store was rude, argumentative, and only replaced the extender after I got a separate Verizon rep on the phone to confirm that the product they had sold me would not work. Very bad experience and I will never go back there.
You would think that the person selling you an extender would at least check if it is compatible with your devices.