According to 'Marca', the Real Madrid board were already unhappy when Hernandez Hernandez and De Burgos Bengoetxea were appointed to referee the Clasico, one as the on-field official and the other as the VAR.
However, their anger has increased after controversial incidents which occurred during the encounter. After the game, Real Madrid complained publically about two penalties not given to Varane.
Real Madrid are especially angry as they feel that the only thing VAR does is "disallow goals". The club use the example of Gareth Bale's goal disallowed on Wednesday when Mendy was given offside. However, it is worth pointing that the VAR did not disallow that goal as it simply confirmed the decision of the assistant referee.
And the thing is Florentino Perez and the rest of board unanimously supported the arrival of the VAR in Spanish football. Therefore, the anger in a controversial situation is even greater.
The club have reiterated their desire to find "justice" in Spanish football, but the board say that the VAR is found wanting in incidents like those which occurred at the Camp Nou.
In addition, Real Madrid believe that sending their complaint to the Spanish FA (RFEF) will not be any use. It is also true that many clubs are issuing statements against the VAR and it will be difficult for the Federation to address all the complaints.