Can't activate the phone with the mistake: "in order to complete the activation of your device please use another phone to call your carrier"

I have no idea what carrier they mean. Device is unlocked according to sickw. what carrier should I call? I am using the overseas one, Vodafone, Ukraine, or Lifecell Ukraine. Still, no idea where to call. My Ukrainian carrirers won't understand me with this question.

ok, today I got more news, but nothing helpful.

1st. Try gsx report from sickw, and they will show you the name of the carrier the flex policity phone got locked with.

The tether policy of such devices is

S2388 US Loaner and Service Picker policy

And it means that device locks to any first carrier you insert into it. Don't know how it works, but smth like that. So, somehow, that device locked to Vodafone, Ukraine, as far as I understand, and gsx shows that... But vodafone, of course has no idea about that.

Still, there is a problem. It doesn't work with vodafone carriers as well... Apple support told, that it may be unlocked to US simcards only. GSX shows totally unlocked, and apple server - same, unlocked. and the apple tech told, it may be locked globally, hah.. I tried the verizon simcard (in roaming) and it didn't work as well. So, everything is really bad with them... Tomorrow I think I'll send the phone back to the seller with all the loses.

yes, thanks. today I was working about this issue, and gsx report showed it's locked to my Ukrainian Vodafone simcard, probably, I used it first to activate the device... I called them as well, but since apple is not that much present in Ukraine and neither of the carriers work with apple, they were really shocked hearing that somehow they may have a device blocked to them... But still, it doesn't work with their carrier, Verizon, US, in roaming and any other way...

Can you provide more details? what are the gsx reports, what carriers are they locked to? are they replacement iPhones?