online sales rep lie to me. my bill increase

1. 5/3/2023, sign up 4 line military 5G GO family plan. online sales rep told I can get “ Free 3 Iphones 14 upgrade trade in and $120/Month all include ”. I confirmed 3 times with him. (saved online chat history can approve.)
2. 5/9/2023 , find out I need to pay $133.77/mo, not $120. by next 24 month. I have to pay total $330.48 difference.  
3. called customer service. they offer me $40 one time discount. but can not honor the sales rep word. 

Not really satisfied the solution. Can any T-mobile staff contact me regarding this issue. Thank you.