The others are SO RIGHT, this is going to be unpleasant for you.  You say you did some research, obviously nowhere near enough.  Have you had your seller account verified and signed up for Managed Payments?  I hope the "Winner" hasn't paid as you are unlikely to see any money.  

The ? you are asking here now should have been done prior to listing anything.  Did you even read "Selling on Ebay" prior?

 

I suspect the listing in USD is because they have copied the listing from a  US seller. You know, that little link under the photo asking if you want to sell a similar item? I suspect they have hit that, which has then spawned a USD listing. They haven't actually looked at what they were posting, just that they were using a listing from someone who sells new phones in all colours, not just black.

 

I also suspect the OP will be back when they realise they have lost both the money and the phones. Sadly, they don't have a leg to stand on and ebay will definitely side with the buyer. 

 

If they haven't posted the latest sale, the best thing they can do is cancel, then do some homework about listing items for sale, especially phones. I highly doubt they'll be back to read the replies, which is unfortunate.