United boss Sir Alex Ferguson has claimed Madrid were a club with "no moral issues at all" as speculation, mostly generated in Spain, suggested the capital club were lining up a move for the 23-year-old Portugal winger.
Calderon, however, insists his club have "conducted themselves exquisitely" in the whole affair.
"I am really surprised to hear what he said about us. I don't understand Ferguson," he told sports daily Marca on Sunday.
"Real Madrid have conducted themselves exquisitely in this whole affair with Cristiano Ronaldo.
"We have always said that he is a player who has a contract and that Manchester United is a club that does not sell. That's everything."