Switch phone for iPhone 13?
I'm an international student currently studying in the US. Shortly after we arrived, my mom went to an AT&T store to buy me a new iPhone with an American number, but at the branch she visited she was told that there were no iPhones available for prepaid plan holders; only postpaid, and I wasn't eligible. The only phone they had in stock at that time was the V340U with Android 10. I needed an American number, so now I have an Android phone with a prepaid Unlimited Monthly plan.
Now that the iPhone 13 is out, I'm wondering if I can swap my Android for an iPhone 13 and if I can do so at no cost? I'm looking to get the baseline iPhone 13 mini.