T-Mobile Bait and Switch

In May we went into a T-Mobile store in Burford, GA and was told we could trade in our iPhone 11s for iPhone 14s and get $830 off and a Samsung Galaxy S21 for $800. All we had to do was switch from the Magenta Max to the Go5G plan. Went through the process and all was good. I have finally received a few bills and finally learned they never gave me the deal which was promised. Now they are telling me I had to have the Go5G Plus plan which is significantly more expensive and there is nothing they can do. Any suggestions on what options I have here?