Billing problem, not receiving offered promotion

I'm looking for assistance resolving a billing problem.  I was provided info in Nov 2023 that convinced me to transfer my mobile service to xfinity. The promotion I was offered has still not been applied to my bill and I have been told numerous stories as to why I have not received it. 

1. I see it hasn't been applied, let me put in the order for you. 

2. I don't see any record of your previous phone call and the order has not been put in, but there's an error when I try to put in the order for you. 

3. You're not eligible for that promotion because you also received new phones.

4. You are eligible for the promotion, and I put in the order for you. You should see it on your next bill. 

5. I'm sorry for the misunderstanding. You're not eligible for that promotion because you're receiving a discounted internet service. Let me read to you what I found that says you're not eligible. No I can't send that document to you because it's not a publicly available document.

I have asked all of these representatives to provide me info in writing. None of them have been able to do so. The manager I spoke to most recently was named Janella. She was unable to provide me her last name.  She told me the only other thing I can do is reach out to corporate.

This is unacceptable service. I was lied to.  Additionally, info that would help me make an informed decision is not publicly available.  I will keep pushing until this has been properly resolved.