False advertising

Today I used the Uber eats app to buy McDonald's it showed a nazo deal buy 1 get 1 free meals. So I ordered 3 double cheese burgers meals and 1 regular meal. The payment was accepted but when we got our meal we just got 3 double Burges and a regular meal so what happened to the buy 1 get 1 free?... We called the manager and she says the dal is not valid. So why would the deal be on the app. This is false publishing and just making money of people. This is not good and it's not the first time having this problem with McDonald's. It's just getting too far now