Scarpi,
Don't go over the top. I apreciate your disapointment but I don't beleive that you were duped. I don't beleive that you have paid too much for the frame in its current condition and with a little patience and a cooler head it could be fixed without too much effort or cost.
Your not in a strong legal position. You may beleive you have the moral highground but so do most people in disputes. If you think your in the worst possible position and nothing could be worse then you just might find out that things can get worse so let it go. Have a sleep on it and consider your options in the morning.
Regards, Anthony