TMobile scam to give free device

Had two older iphones paid off. Walked in to see about their iPhone 15 promotion last year. Was told if you upgrade your plan you get credit for your old phones, the iPhone 15's would be free with the 5g plan upgrade, and my new monthly bill would go from $117 to $130 after the credits expired and would not go up after that. I'm now being charged over $1k for two phones, my monthly bill is almost $160. I pay almost $70 a month for the 2 phones they told me were free. Contacted t-mobile directly to see if they could help…they couldn't. Looking at these past reviews I see I'm not the only one who got scammed.