Out of new Iphone and $300 [Edited]

I switched from verizon to xfinity mobile today. When on the phone and switching, they ran a credit check and my accounts were frozen so the credit check didn't go through. This prevented the promotional credit from being applied to trade in my current iphone 14 for the iphone 17 pro max. When talking to the agent on the phone, he said I could just transfer the service to xfinity on my iphone 14, and then trade in my phone later once the credit check went through and get the same promotion. What he failed to mention, is that I am now considered an existing line and the promotional credit is like $300 less than before. Also, I am now told I need to wait an additional 6 months to build credit with xfinity before i am eligible for the promotion even though i have an excellent credit score. I called back an xfinity agent to explain the situation and they were no help. They put in a ticket and told me to go to the store. I went to the store and they put in a credit request escalation but basically told me again that I would have to wait 6 months and would not get the new line promotional credit. I am very frustrated and would just like the original offer that I was promised.

[Title Edited: "Inappropriate Language"]