Pompey boss Harry Redknapp had an improved £4.1million bid knocked back by the Spaniards last summer.
Redknapp is still keen to sign the player - dubbed Spiderman over his extravagant goal celebrations. But Portsmouth may find it impossible to go back with another bid in January after the Spaniards' accusations.
Grande rapped: "Portsmouth insulted Jonas by undervaluing him and manipulating him.
"They are not complying with UEFA laws which state you cannot negotiate with players if you do not have permission from their clubs."