Trade in promo - beware

I did a trade in for an Iphone for my pixel 6 pro unlocked. 

The promo was for 800 dollar trade in. The pixel pro was UNLOCKED and I have proof of purchase for it being bought unlocked. 

Get an email today, the trade in now went down to 345 because it's a Verizon pixel 6 pro. 

They basically told me there's nothing they can do right now and I'd just have to wait until my next billing cycle for them to look into it. I told them to look up the IMEI and it shows it's unlocked.

Ive been a customer for years, but this, this has brought me to the point of switching. 

Re: Trade in promo - beware
Customer Service Rep

Congratulations on getting a new phone, Slamone! That is always an exciting time. We are sorry to learn that there were some complications when it comes to the trade-in promotion expectations. We will need to gather more information about the upgrade and the promotion, so we have sent a private note to you.