SIM Not Valid on replacement unlocked Verizon iPhone
I got an iPhone 6s recently, but more recently I cracked the screen, and when I went in to Apple Store, they kindly provided a new replacement phone rather than a screen replacement because, they said, screen replacements for the 6s was not yet available. So, it all worked fine in the US for a month or so, but now I've come to another country, and I put in a different known-working SIM card, and it at first said "Activation Required" (whereas on another iPhone with the same SIM card it just immediately started using the SIM card just fine). When I went through a couple of first steps of the activation, it put up a screen that said
SIM Not Valid
The SIM card inserted in this iPhone does not appear to be supported. The SIM card that you currently have installed in this iPhone is from a carrier that is not supported under the activation policy that is currently assigned by the activation server. This is not a hardware issue with the iPhone. Please insert another SIM card from a supported carrier or request that this iPhone be unlocked by your carrier. Please contact Apple for more information.
I then called Verizon, and they told me that they do not lock iPhones. They said I should contact Apple. I called Apple Care, and the person I spoke to made me do restore-from-itunes procedure, which by the way was extremely painful, since took hours and many retries due to a combination of buggy Hotel Internet connection, needing to download a whole 2 GB update, iTunes not being able to resume an aborted download. After the restore from iTunes, it just gave me the same problem.
When I called Apple, I asked if the person was familiar with this problem, and he claimed he was, and that this is how you fix it, but I don't think he really was. It is described extremely well in this other discussion here: Re: SIM Not Valid but unlocked?
The post says stuff about needing get to second level support or senior engineer, etc., and I tried to use all that language, but after just getting past triage, all I got was a first-line guy who claimed he could fix this. But his "fix" did nothing. He also answered when I asked how this happened that something "glitched" when I first put in the SIM card; but that was proven wrong when I restored from a backup that was from a day before my trip, and nothing improved at all.
Why can't Apple Care reps learn about this problem and immediately deal with it effectively or pass users on to someone who can? Does anyone know of any official statement of this problem and how to deal with it from Apple?
I'm still in support ****, waiting for the sun to rise in Cupertino. I'll keep you posted when/if this gets resolved.