False advertising of buy 1 get 1 free

I ordered a pizza on their Buy 1 Get 1 Free deal. I got 1 pizza.

I brought this up, and they said that "The restaurant is not offering a buy 1 get 1 free deal".

I then provided a screenshot showing that their app shows the restaurant as participating.

They rep**** with what was basically the same response.

I provided another screenshot, from within the app, showing I could order the exact same item, advertised as Buy 1 Get 1 free.

I got the same response.

I asked to be escalated to a manager, and got the same response.

This is a week later, and the restaurant is still shown on their site as participating in the Buy 1 Get 1 Free deal.