Trade in value of my iPhone misrepresented

There is so much false advertising with T-Mobil. Like the commercial with Snoop Dogg; bring in any used I phone and get the iPhone 16 on us new and existing customers. That is absolutely not the case. When you try to upgrade it gives you a lousy $150 to $300 credit. My husband was offered $800 credit for his iPhone 13 and my son received a $300 credit for his iPhone 14 Pro Max . Makes no sense. I will be calling tomorrow. It’s like the calling does not make a difference, there is no good customer service provided. Sprint never did their customers like this. I loved sprint service. With over 6 lines I will not be sticking around due to this false advertisement that T Mobil has and lack of customer service.