apple lost trade in

I trade in an iPhone 11pro max and they said I have trade in iPhone XR. And that is they phone I send in. Which it is not. I have call this not less than 5times. First, they told me they send the wrong phone back, so they going to send the iPhone 11pro max back to me. And now they told me I have not call an once. They told me to wait and won’t give any confirmation email. Just leave you hanging. So now, I am not able to locate my phone, because when you trade in, they told you to turn the find my iPhone off. “So, they can steal your phone? And tell you that is the phone you send it in?”