Google pixel trade in nightmare

I preordered the Google pixel 10 pro XL on release day and set up my 9 pro XL as a trade in. The trade in offer was $1,000 off if I send my 9 pro XL back in. My new phone came but I never received a shipping label for my old phone. I went to an Xfinity store and they said they could see where the trade in was initiated but Xfinity was mailing me a shipping label. No big deal. It's been a week and I haven't received the shipping label. I chatted with someone online yesterday and they said they couldn't do anything on their end and I had to call in. I called today and the representative I talked to basically said the trade in value was a lie and I was given $400 off, or a credit of $16.66 per bill cycle, but I still had to send my old phone in to get that credit. The credit is already on my bill and my new phone says nothing about a trade in. The rep asked for my account information specifically, including account number, phone number, and wanted my full card number, but that's when I hung up the phone. I just want to credit for my old phone. Anything I can do or am I [Edited: Language]?