Honesters and liers

There are two kinds of people on a mysterious island. There are so-called Honesters who speak always the truth, and the others are liers who always lie.
Three fellows (A, B and C) are having a quarrel at the market. A gringo goes by and asks the A fellow: "Are you an Honester or a lier?" The answer is incomprehensible so the gringo asks B: "What did A say?" B answers: "A said that he is a Swindlecant." And to that says the fellow C: "Do not believe B, he is lying!" Who is B and C?

they?