How can I find out the carrier?

I bought a iPhone 7+ and told it was unlocked (which wasn't the case). The person isn't responding to my messages either and it didn't have a sim when I got it. The network says not available! I don't know who the service is through and can't use the phone cause it says SIMS NOT SUPPORTED is there a way I can find out who the carrier is?

"It was a great deal!"

You bought a stolen or "found" phone that was not the property of the person who sold you the phone.

Contacting the carrier will do nothing.

Assuming it was reported missing or stolen by the real owner, the phone is blacklisted and will not be activated by any carrier.

You should contact the person who sold you the phone and either have them unlock it or get your money back. If the person who sold it to you continues to not respond, contact Law Enforcement and file a report… And consider this a learning event.

If the person that sold it won't help and you used a credit card for the sale request a refund from your credit card.

To unlock it you need an unlock code from the provider, you need to know that info to unlock it.