Scammed with expired promotion

Got a call from att about the promotion to upgrade my s7 to a s23. They told me it would be completely free so I agreed and they shipped my phone this was all on 05-18-23 turns out that promotion was over on 05-12-23. So they sold me a phone under false pretenses knowing that the promotion was over now I’m stuck with a 1000$ bill and they will not do anything about it even though they know there sales person lied and they have records of everything that was done