Complaint to xfinity mobile support assistant

As new iphone 12 preorder started and there's a good deal on xfinity mobile, I wanted to move my carrier to xfinity mobile. But I had some questions about the deals so I started the chat for the support. And the assistant replied very slow.. That's fine. I can wait for ~5 min to get an answer.. Then, I asked a few more things and the assistant just left without any notice. If she/he doesn't know how to answer, she/he should tell me before she/he left. I'm so disappointed with your service. 

My question was pretty simple. Is the iPhone unlocked if I pay in full and is there any contract such as 2 years contract to get the deal? 

I don't understand why he/she just left without any comments/answers.