Did you ask about whether there had been an equipment change?

I am personally not persuaded by your argument that "only the website" says that not all business class are lie-flat. Was there something at the airport, at the time you bought the seat, that told you everything *was* lie-flat? Or was that just an assumption you made from other information you saw another time?

I think you should lose your credit-card charge back. You did get a much bigger seat, much better food and drink, etc.