Funny, just upgraded my 5S to a 7.
Took all of 15 minutes, longer than regular mostly because of it being a business account. The data transfer was definitely less than 5 minutes. But then this was a Sprint store.
I will say that our Apple store is always busy and waiting to talk to someone isn’t uncommon, even with 20 or so employees on the floor.
All I can figure is that there may be incompatibilities between the AR and US cell phone systems that were causing an issue. That, or the Apple employee was a moron.
Its some sort of tax issue between Apple and the AR government.