Fake and deceptive t mobile promotion

After reading through these complaints it seems that T-Mobile has an issue with following up with promises.  I had a Galaxy Note 20 Ultra, and I was going to trade it in with Samsung for $600, but they required a credit check.  I don't want them messing with my credit so I opted to keep my Note device.  I later discovered that T-Mobile was offering $500 to trade in the device for the Galaxy S24 Ultra.  I decided to do it since I had been a customer for so  long.  I got the email stating that my trade in was accepted, and they confirmed on the website that the assessed value matches the estimated value.  I just logged into my account and discovered that T-Mobile only gave me $120 for my Note.  I would have kept the phone if this was the offer.  My Note was in excellent condition, and I had never even dropped it.  The way it T-Mobile owes me an additional $380 in credit to my account.  This is blatantly false, and misleading advertising.  They only seem to get away with this because they are so large.  Smaller companies would giv e about their customer's finances.  I have been a customer for a very long time, and this is unacceptable behavior.